7Baggers

Natural Resource Partners L.P
(NYSE:NRP) 

NRP stock logo

Natural Resource Partners L.P., through its subsidiaries, owns, manages, and leases a portfolio of mineral properties in the United States. It operates in two segments, Coal Royalty and Other, and Soda Ash. The company owns interests in coal, soda ash, trona, and other natural resources. Its coal re...

Founded: 2002
Sector: Energy
Industry: Thermal Coal

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    Unit: USD2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 2018-12-31 2018-09-30 2018-06-30 2018-03-31 2017-12-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 2013-12-31 2013-09-30 2013-06-30 2013-03-31 2012-12-31 2012-09-30 2012-06-30 2012-03-31 2011-12-31 2011-09-30 2011-06-30 2011-03-31 2010-12-31 2010-09-30 2010-06-30 2010-03-31 2009-12-31 2009-09-30 2009-06-30 2009-03-31 2008-12-31 2008-09-30 2008-06-30 2008-03-31 2007-12-31 2007-09-30 2007-06-30 2007-03-31 2006-12-31 2006-09-30 2006-06-30 2006-03-31 2005-12-31 2005-09-30 2005-06-30 2005-03-31 2004-12-31 2004-10-17 2004-09-30 2004-06-30 2004-03-31 2003-12-31 2003-10-17 
                                                                                              
      revenues and other income
                                                                                              
      royalty and other mineral rights
    49,615,000 44,295,000                                                                                         
      transportation and processing services
    1,800,000 2,551,000                      3,685,000 3,865,000                                                                  
      equity in earnings of sisecam wyoming
    -2,390,000 2,526,000                                                                                         
      gain on asset sales and disposals
    906,000 729,000 247,000  1,000 4,643,000 165,000  854,000 5,000 96,000  354,000          256,000 -111,000 6,107,000                                                                  
      total revenues and other income
    49,931,000 50,101,000 55,928,000                     53,054,750 63,709,000 238,000 -8,000         88,112,000 97,874,000 118,246,000 102,751,000 116,063,000 125,479,000 137,630,000 109,677,000 137,273,000 91,609,000 90,561,000 80,309,000 94,744,000 82,237,000                                          
      operating expenses
                                                                                              
      operating and maintenance expenses
    7,654,000 4,159,000   6,762,000 5,846,000 5,671,000  8,305,000 7,916,000 7,005,000  7,867,000          5,186,000 5,676,000 5,994,000 27,000 27,000 -1,249,000 6,790,000 8,117,000 6,215,000 -3,364,000 6,348,000 5,419,000 7,384,000 31,797,000 31,242,000 29,797,000 30,902,000                                                    
      depreciation, depletion and amortization
    3,868,000 3,754,000 3,985,000 10,517 4,725,000 3,320,000 4,649,000 13,471 4,589,000 3,787,000 4,079,000  6,850,000          2,012,000 3,186,000 3,384,000   18,356,000 4,888,000 5,376,000 5,100,000 20,413,000 5,305,000 5,375,000 6,973,000 10,906,000 11,929,000 10,472,000 14,021,000 18,152,000 26,624,000 30,660,000 25,392,000 30,258,000 18,621,000 16,350,000 14,647,000 14,352,000 17,852,000 17,411,000 14,762,000 16,155,000 14,485,000 15,172,000 12,409,000 15,477,000 19,153,000 16,166,000 14,322,000 12,930,000 16,195,000 16,485,000 11,368,000 11,986,000 12,952,000 21,996,000 13,078,000 15,405,000 17,042,000 16,748,000 15,059,000 14,067,000 13,045,000 12,527,000 11,752,000 7,597,000 7,009,000 7,236,000 7,853,000            
      general and administrative expenses
    5,725,000 5,597,000  1,483,750    1,417,250    1,129,500            3,199,750 4,253,000                                                                  
      asset impairments
      20,000  87,000 69,000   63,000 69,000   812,000           147,730,000 484,000           9,245,000 5,697,000 91,000 2,030,000 50,953,000 626,838,000 3,803,000  20,585,000  5,624,000    443,000 291,000                                        
      total operating expenses
    17,247,000 13,510,000                      12,960,500 14,115,000 27,000 27,000         61,006,000 58,967,000 47,505,000 55,595,000 114,021,000 701,769,000 81,710,000 69,260,000 106,223,000 36,582,000 40,158,000 27,870,000 27,992,000 30,613,000 31,472,000 31,804,000                                        
      income from operations
    32,684,000 36,591,000                      40,094,250 49,594,000           27,106,000 38,907,000 70,741,000 47,156,000 2,042,000 -576,290,000 55,920,000 40,417,000 31,050,000 55,027,000 50,403,000 52,439,000 66,752,000 51,624,000 55,332,000 62,528,000 73,206,000 65,643,000 63,492,000 64,824,000 -19,000 -16,523,000 64,816,000 55,861,000 52,852,000 50,344,000 51,952,000 40,912,000 43,502,000 41,395,000 27,661,000 41,417,000 55,252,000 53,882,000 47,105,000 40,768,000 35,514,000 35,316,000 29,078,000 28,391,000 27,619,000 28,569,000 27,964,000 31,624,000 27,624,000 23,962,000 27,211,000 22,673,000  16,655,000 21,707,000 17,472,000 14,258,000   
      yoy
                                       1227.42% -106.75% 26.50% 16.67% -93.42% -1147.29% 10.95% -22.93% -53.48% 6.59% -8.91% -16.14% -8.82% -21.36% -12.85% -3.54% -385394.74% -497.28% -2.04% 16.05% -100.04% -132.82% 24.76% 36.54% 21.49% 21.62% 87.82% -1.22% -21.27% -23.17% -41.28% 1.59% 55.58% 52.57% 62.00% 43.59% 28.59% 23.62% 3.98% -10.22% -0.02% 19.23% 2.77% 39.48%  43.87% 25.36% 29.77%        
      qoq
    -10.68%                       -19.16%            -30.33% -45.00% 50.01% 2209.30% -100.35% -1130.56% 38.36% 30.17% -43.57% 9.17% -3.88% -21.44% 29.30% -6.70% -11.51% -14.59% 11.52% 3.39% -2.05% -341278.95% -99.89% -125.49% 16.03% 5.69% 4.98% -3.10% 26.98% -5.95% 5.09% 49.65% -33.21% -25.04% 2.54% 14.39% 15.54% 14.79% 0.56% 21.45% 2.42% 2.80% -3.33% 2.16% -11.57% 14.48% 15.28% -11.94% 20.01%   -23.27% 24.24% 22.54%    
      operating margin %
    Infinity% Infinity% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% Infinity% Infinity% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% NaN% Infinity% Infinity% Infinity% Infinity% Infinity% -Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% 63.74% 66.29% 71.47% 69.70% 70.03% 70.56% -0.02% -15.92% 70.91% 65.83% 68.16% 62.34% 65.28% 64.41% 66.01% 64.72% 46.50% 62.06% 72.87% 70.71% 62.31% 63.65% 61.96% 62.65% 56.91% 56.55% 66.28% 68.86% 68.23% 67.97% 65.19% 61.86% 65.26% 62.55%  73.96% 63.43% 59.23% 54.09%   
      interest expense
    -1,779,000 -2,380,000  1,048,500                    -9,265,250 -10,431,000           -23,305,000 -22,491,000 -22,054,000 -23,748,000 -23,830,000 -23,711,000 -23,343,000 -22,943,000 -22,426,000 -18,862,000 -19,037,000 -19,860,000 -19,777,000 -15,516,000 -14,440,000 -14,663,000 -13,157,000 -13,677,000 -13,578,000 -13,560,000 -13,385,000 -12,779,000 -12,429,000 -10,587,000 -10,356,000 -10,204,000 -10,346,000 -10,729,000 -10,592,000 -10,762,000 -10,675,000 -8,079,000 -7,020,000 -6,912,000 -7,064,000 -7,360,000 -7,106,000 -7,124,000 -7,133,000 -7,327,000 -5,170,000 -3,960,000 -3,675,000 -3,618,000 -1,979,000 -2,889,000 -2,570,000 -2,457,000  -2,355,000 -2,417,000 -2,404,000 -3,136,000   
      net income
    30,905,000 34,211,000 40,253,000 -140,688,356 38,595,000 46,064,000 56,213,000 -213,176,565 63,846,000 70,334,000 79,275,000 63,218,000 74,555,000 66,820 63,899,000 108,848,739 29,498 15,382 8,381,000 14,687 7,216 -125,501 18,779,000 -118,698,000 39,170,000 19,351,000 35,719,000 49,058,000 28,541,000 39,089,000 26,074,000 30,707,000 26,066,000 49,950,000 16,764,000 3,488,000 23,531,000 46,446,000 23,427,000 -21,786,000 -600,001,000 32,578,000 17,489,000 8,645,000 36,173,000 31,407,000 32,605,000 46,981,000 36,126,000 41,065,000 47,906,000 60,107,000 52,001,000 49,938,000 51,309,000 -14,322,000 -29,286,000 52,352,000 45,282,000 42,506,000 40,153,000 41,610,000 30,191,000 32,927,000 30,651,000 17,082,000 33,420,000 48,463,000 47,338,000 40,353,000 33,852,000 29,059,000 28,928,000 22,631,000 21,881,000 23,248,000 25,274,000 25,044,000 28,524,000 24,955,000 21,465,000 24,972,000 20,447,000  13,324,000 19,368,000 15,128,000 11,174,000   
      yoy
    -19.92% -25.73% -28.39% -34.00% -39.55% -34.51% -29.09% -437.21% -14.36% 105158.90% 24.06% -41.92% 252645.95% 334.40% 662.43% 741023.03% 308.79% -112.26% -55.37% -100.01% -99.98% -100.65% -47.43% -341.95% 37.24% -50.50% 36.99% 59.76% 9.50% -21.74% 55.54% 780.36% 10.77% 7.54% -28.44% -116.01% -103.92% 42.57% 33.95% -352.01% -1758.70% 3.73% -46.36% -81.60% 0.13% -23.52% -31.94% -21.84% -30.53% -17.77% -6.63% -519.68% -277.56% -4.61% 13.31% -133.69% -172.94% 25.82% 49.99% 29.09% 31.00% 143.59% -9.66% -32.06% -35.25% -57.67% -1.28% 66.77% 63.64% 78.31% 54.71% 25.00% 14.46% -9.64% -23.29% -6.84% 17.75% 0.29% 39.50%  61.10% 28.93% 35.16%        
      qoq
    -9.66% -15.01% -128.61% -464.52% -16.21% -18.05% -126.37% -433.89% -9.22% -11.28% 25.40% -15.21% 111475.88% -99.90% -41.30% 368903.79% 91.77% -99.82% 56964.07% 103.53% -105.75% -100.67% -115.82% -403.03% 102.42% -45.82% -27.19% 71.89% -26.98% 49.92% -15.09% 17.80% -47.82% 197.96% 380.62% -85.18% -49.34% 98.26% -207.53% -96.37% -1941.74% 86.28% 102.30% -76.10% 15.17% -3.67% -30.60% 30.05% -12.03% -14.28% -20.30% 15.59% 4.13% -2.67% -458.25% -51.10% -155.94% 15.61% 6.53% 5.86% -3.50% 37.82% -8.31% 7.43% 79.43% -48.89% -31.04% 2.38% 17.31% 19.20% 16.49% 0.45% 27.82% 3.43% -5.88% -8.02% 0.92% -12.20% 14.30% 16.26% -14.04% 22.13%   -31.21% 28.03% 35.39%    
      net income margin %
    Infinity% Infinity% Infinity% -Infinity% Infinity% Infinity% Infinity% -Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% -Infinity% Infinity% -Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% -Infinity% -Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% Infinity% 47.31% 50.78% 58.68% 55.22% 55.08% 55.85% -14.67% -28.22% 57.27% 53.37% 54.82% 49.72% 52.28% 47.53% 49.96% 47.92% 28.72% 50.08% 63.92% 62.13% 53.38% 52.85% 50.70% 51.32% 44.29% 43.58% 55.79% 60.91% 61.11% 61.31% 58.89% 55.41% 59.89% 56.41%  59.17% 56.60% 51.29% 42.39%   
      less: income attributable to preferred unitholders
       1,146,852 -655,000 -1,443,000  2,690,306 -786,000 -1,321,000 -586,000 -7,500,000 -7,500,000 -7,500 -7,500,000 -5,882.5 -7,961 -7,842 -7,727,000 -7,612 -7,500 -7,613  -5,625,000 -7,500,000 -7,500,000 -7,500,000    7,500,000 7,765,000 7,650,000 7,538,000 2,500,000                                                        
      less: redemption of preferred units
       24,460,515 -10,819,000 -13,666,000  60,868,071 -17,083,000 -27,618,000 -16,228,000                                                                                
      net income attributable to common unitholders and the general partner
    30,905,000 34,211,000          55,718,000 67,055,000 59,320 56,399,000 7,432.75 21,537 7,540 654,000                                                                        
      net income attributable to common unitholders
    30,287,000 33,527,000 39,448,000 -109,744,187 26,578,000 30,336,000 52,982,000 -135,002,229 42,951,000 36,990,000 55,258,000 54,603,000 65,714,000 58,134 55,271,000 7,284 21,106 7,389 641,000     17,576,250 31,036,000 11,614,000 27,655,000    18,203,000 22,484,000 18,046,000 41,495,000 14,048,000                                                        
      net income attributable to the general partner
    618,000 684,000                      358,750 634,000                                                                  
      net income per common unit
                                                                                              
      basic
    2,310 2,550                      1,432.5 2,530                                                                  
      diluted
    2,280 2,520                      980 1,660                                                                  
      comprehensive income from unconsolidated investment and other
    -2,391,000 -414,000                      -85,000 -520,000                  -965,000                                                
      comprehensive income
    28,514,000 33,797,000                      23,475,000 38,650,000             46,908,000 22,882,000     8,458,000 36,543,000 31,243,000 32,504,000 46,900,000 36,167,000 41,116,000 47,960,000 60,120,000 52,015,000 49,951,000 51,319,000                                    
      basic net income per common unit
      3,010 -8,458.31 2,040 2,330 4,130 -10,704.41 3,400 2,930 4,400 4,360 5,250 4.65 4,450 0.59 1.71 0.6 50       950 2,260    1,490 1,830 1,480 3,390 1,150                                                        
      weighted-average common units—basic
      13,098,000 12,991 13,049,000 13,032,000 12,832,000 12,619 12,635,000 12,635,000 12,570,000 12,484,000 12,506,000 12,506 12,415,000 12,337,000 12,351 12,351 12,292,000 12,261 12,261 12,261 12,261,000 12,260,000  12,261,000 12,255,000 12,244,000 12,246,000 12,246,000 12,238,000 12,232,000 12,232,000 12,232,000 12,232,000                                                        
      diluted net income per common unit
      2,970 -8,198.65 2,000 2,290 3,830 -8,866.92 2,910 2,490 3,440 3,150 3,710 3.29 3,110 4,808.02 1.1 0.56 50 0.56 -0.02 -10.64 520     2,700 1,300 1,750 1,150 1,310 1,070 1,130 20                                                        
      plus: dilutive effect of preferred units
       -374,719   775,000 -2,431,941 1,104,000 2,420,000 3,778,000 -34,000 6,210,000 6,292 6,974,000 9,590,165 13,835 14,351     23,187,000     -1,645,000 9,124,000 8,615,000 9,463,000 509,000 11,523,000 9,760,000 2,391,000                                                        
      plus: dilutive effect of warrants
       -185,861  35,000 521,000 -1,294,798 1,492,000 1,139,000 1,255,000 24,000 807,000 937 531,000             37,000 470,000 522,000 424,000 -30,000 225,000 467,000 322,000                                                        
      plus: dilutive effect of unvested unit-based awards
      206,000 -228,764 222,000 200,000 265,000 -189,784 240,000 122,000 209,000 6,000 195,000 178 240,000 177,856 188 119 116,000                                                                        
      weighted-average common units—diluted
      13,304,000 13,647 13,271,000 13,267,000 14,393,000 16,096 15,471,000 16,316,000 17,812,000 19,653,000 19,718,000 19,913 20,160,000 22,193,000 26,374 26,821 12,408,000 12,261 12,261 12,261 35,448,000 12,260,000    20,234,000 21,840,000 21,383,000 22,125,000 21,950,000 23,980,000 22,459,000 14,945,000                                                        
      diluted net income attributable to common unitholders and the general partner
      40,253,000 -115,080,989 27,121,000 30,955,000 56,213,000 -149,618,188 45,977,000 41,395,000 62,461,000 63,218,000 74,555,000 66,820 63,899,000 108,848,739 29,498 15,382 654,000                                                                        
      less: diluted net income attributable to the general partner
      -805,000 2,301,840 -543,000 -619,000 -1,124,000 2,992,704 -920,000 -828,000 -1,249,000 -1,026,250 -1,491,000 -1,336 -1,278,000    -13,000    -376,000     -981,000 -578,000 -765,000                                                             
      diluted net income attributable to common unitholders
      39,448,000 -112,779,149 26,578,000 30,336,000 55,089,000 -146,625,484 45,057,000 40,567,000 61,212,000 61,953,000 73,064,000 65,484 62,621,000 106,671,804 28,909 15,074 641,000 6,934 -279 -130,452 18,403,000     48,077,000 28,322,000 37,455,000 25,553,000 30,093,000 25,545,000 25,401,000 311,000                                                        
      for the three months ended march 31, 2025
                                                                                              
      revenues
      55,681,000  52,217,000 57,252,000 70,799,000  73,112,000 64,277,000 79,869,000  87,348,000          33,942,000     166,117,000 49,371,000 53,901,000 51,593,000 167,613,000 49,413,000 49,626,000 51,138,000                                                        
      less:
                                                                                              
      compensation
      1,938,000                                                                                        
      long-term incentive compensation
      464,000                                                                                        
      property taxes
      1,792,000                                     2,150,500 2,528,000 3,070,000 3,004,000 2,744,000 3,520,000 3,378,000 3,967,000 3,611,000 4,009,000 3,849,000 3,947,000 3,852,000 3,602,000 3,331,000 4,488,000 3,077,000 2,974,000 3,577,000 3,012,000 2,285,000 3,552,000 2,782,000 2,651,000 2,600,000 3,311,000 2,514,000 3,211,000 2,040,000 2,263,000 3,105,000 2,392,000 2,449,000 2,963,000 2,645,000 2,228,000 1,144,000 1,532,000 1,546,000 1,749,000 1,983,000 1,552,000 1,547,000 1,434,000  1,388,000 1,377,000 1,278,000 1,306,000   
      other segment items
      2,521,000                                                                                        
      as of march 31, 2025
                                                                                              
      total assets
      505,073,000                                                                                        
      for the three months ended march 31, 2024
                                                                                              
      as of december 31, 2024
                                                                                              
      for the three months ended september 30, 2024
                                                                                              
      for the three months ended september 30, 2023
                                                                                              
      for the nine months ended september 30, 2024
                                                                                              
      for the nine months ended september 30, 2023
                                                                                              
      for the three months ended june 30, 2024
                                                                                              
      for the three months ended june 30, 2023
                                                                                              
      for the six months ended june 30, 2024
                                                                                              
      for the six months ended june 30, 2023
                                                                                              
      for the three months ended march 31, 2023
                                                                                              
      other expenses
           959,250    1,906,250                                                                               
      for the three months ended september 30, 2022
                                                                                              
      for the nine months ended september 30, 2022
                                                                                              
      for the three months ended june 30, 2022
                                                                                              
      for the six months ended june 30, 2022
                                                                                              
      for the three months ended march 31, 2022
                                                                                              
      allocation of net income
                                                                                              
      less: net income attributable to the general partner
               -913,750 -1,341,000 -1,186 -1,128,000    -13,000       -237,000 -564,000        216,000                                                        
      for the three months ended september 30, 2021
                                                                                              
      for the nine months ended september 30, 2021
                                                                                              
      for the three months ended june 30, 2021
                                                                                              
      asset impairment
                                  242,000   91,000 1,778,000                     22,733,000 90,932,000                                  
      for the six months ended june 30, 2021
                                                                                              
      for the three months ended march 31, 2021
                                                                                              
      add (less): net loss attributable to the general partner
                   -148.75 -431 -151                                                                         
      add (less): diluted net loss attributable to the general partner
                   -2,176,935 -589 -308  -141 2,662                                                                     
      for the three months ended september 30, 2020
                                                                                              
      for the nine months ended september 30, 2020
                                                                                              
      for the three months ended june 30, 2020
                                                                                              
      for the six months ended june 30, 2020
                                                                                              
      for the three months ended march 31, 2020
                                                                                              
      diluted income per common unit
                                                                                              
      net income from continuing operations
                       14,687 7,216 -125,501 18,779,000 -119,448,000 39,163,000 19,106,000 35,765,000 31,299,000 28,565,000 39,123,000 26,088,000 30,741,000 26,499,000 49,817,000 16,971,000 3,811,000 16,419,000 48,633,000                                                     
      diluted net income from continuing operations attributable to common unitholders and general partner
                       -30,529.75 -284 -133,114      31,299,000 28,924,000 38,254,000                                                             
      add (less): diluted net loss from continuing operations attributable to the general partner
                       610.5 2,662                                                                     
      diluted net income from continuing operations attributable to common unitholders
                       6,934 -279 -130,452 18,403,000     30,673,000 28,346,000 37,488,000 25,567,000 30,126,000 25,969,000 25,271,000 514,000                                                        
      diluted net income from discontinued operations attributable to common unitholders
                                 -33,000  -33,000 -424,000 130,000                                                         
      diluted net income attributable to common unitholders and general partner
                       -30,529.75 -284 -133,114      49,058,000 28,900,000 38,220,000                                                             
      diluted net income from continuing operations per common unit
                       0.56 -0.02 -10.64 520     1,840 1,300 1,750 1,160 1,310 1,080 1,130 30                                                        
      diluted net income from discontinued operations per common unit
                                    -20 10                                                         
      for the three months ended september 30, 2019
                                                                                              
      income from discontinued operations
                           51,500 7,000 211,000          -323,000 7,112,000                                                      
      for the nine months ended september 30, 2019
                                                                                              
      for the three months ended june 30, 2019
                                                                                              
      for the six months ended june 30, 2019
                                                                                              
      less: diluted net income from continuing operations attributable to the general partner
                          -376,000     -452,750 -578,000 -766,000                                                             
      diluted net loss from discontinued operations attributable to common unitholders
                               -17,750 -24,000  -14,000    -203,000                                                        
      diluted net loss from discontinued operations per common unit
                                      -10                                                        
      for the three months ended march 31, 2019
                                                                                              
      loss from discontinued operations
                              -35,000           -2,187,000                                                     
      coal royalty and other
                           38,509,250 39,919,000           28,184,000 27,504,000                                                      
      equity in earnings of ciner wyoming
                           9,208,250 13,818,000           9,319,000 10,753,000 10,188,000 9,801,000                                                    
      other incomes
                                                                                              
      loss on extinguishment of debt
                           -7,320,500                                                                   
      total other incomes
                           -16,585,750 -10,431,000                                                                  
      net income (income) attributable to non-controlling interest
                                                                                              
      net income attributable to nrp
                           23,560,000 39,170,000           23,351,000 23,531,000 46,446,000  -137,483,500 -598,757,000 31,334,000 17,489,000                                                
      net income attributable to common unitholders and general partner
                           17,935,000 31,670,000 11,851,000 28,219,000                                                                
      income from continuing operations per common unit
                                                                                              
      basic
                           1,430 2,530                                                                  
      diluted
                           977.5 1,660                                                                  
      comprehensive loss (income) attributable to non-controlling interest
                                                                                              
      comprehensive income attributable to nrp
                           23,475,000 38,650,000           23,178,000 22,922,000   -137,956,250 -599,893,000 31,544,000 16,524,000                                                
      construction aggregates
                                                                                              
      road construction and asphalt paving services
                                                                                              
      oil and gas
                                          7,298,000                                                    
      gain on asset sales
                             238,000 -8,000 2,278,000  168,000 651,000 3,528,000 154,000 3,184,000 29,000 1,801,000 6,426,000 -1,071,000 21,925,000                                                    
      date paid
                                                                                              
      2019
                                                                                              
      february 2019
                                                                                              
      may 2019
                                                                                              
      2018
                                                                                              
      february 2018
                                                                                              
      may 2018
                                                                                              
      less: net income attributable to non-controlling interest
                                 -869,000            -1,244,000                                                 
      net income from continuing operations attributable to common unitholders and general partner
                             11,606,000 28,265,000                                                                
      less: net income from continuing operations attributable to the general partner
                             -232,000 -565,000        220,000                                                        
      net income from continuing operations attributable to common unitholders
                             11,374,000 27,700,000    18,217,000 22,517,000 18,470,000 41,365,000 14,251,000                                                        
      net income from discontinued operations
                             245,000      -34,000 -433,000 133,000                                                         
      less: net income from discontinued operations attributable to the general partner
                             -5,000      -1,000 -9,000 3,000                                                         
      net income from discontinued operations attributable to common unitholders
                             240,000      -33,000 -424,000 130,000                                                         
      basic net income from continuing operations per common unit
                             930 2,260    1,490 1,840 1,510 3,380 1,170                                                        
      basic net income from discontinued operations per common unit
                             20       -30 10                                                         
      net loss from discontinued operations
                              -46,000    -14,000    -207,000                                                        
      less: net loss from discontinued operations attributable to the general partner
                              1,000        -4,000                                                        
      net loss from discontinued operations attributable to common unitholders
                              -45,000    -14,000    -203,000                                                        
      basic net loss from discontinued operations per common unit
                                      -20                                                        
      diluted income per common unit:
                                                                                              
      add (less): net loss attributable to non-controlling interest
                               -127,500 359,000                                                              
      three months ended september 30, 2018
                                                                                              
      intersegment revenues
                               -14,500 58,000 74,000 41,000 373,000 78,000 68,000 62,000                                                        
      general and administrative
                                       6,303,000 4,268,000 3,173,000 3,235,000 -7,793,000 5,140,000 2,234,000 7,454,000 13,887,000 7,664,000 9,029,000 5,857,000 9,052,000 7,305,000 8,878,000 11,586,000 5,510,000 8,225,000 7,029,000 8,950,000 7,397,000 5,521,000 6,439,000 10,196,000 7,790,000 8,761,000 6,794,000 6,548,000 5,176,000 4,586,000 5,834,000 7,506,000 1,151,000 1,732,000 6,890,000 4,149,000 4,168,000 3,687,000 5,559,000 6,634,000 4,510,000 3,475,000 3,420,000 4,115,000 2,318,000 3,527,000 3,162,000 3,312,000  3,847,000 2,523,000 2,422,000 2,711,000   
      other expense
                               2,000    14,750    -16,809,000 -22,488,000 -22,108,000  -17,495,250 -23,711,000                                                  
      three months ended september 30, 2017
                                                                                              
      three months ended june 30, 2018
                                                                                              
      three months ended june 30, 2017
                                                                                              
      allocation of net income:
                                                                                              
      less: net income from continuing operations and income attributable to preferred unitholders allocated to the general partner
                                  371,000 459,000 379,000 914,000                                                         
      less: net income and income attributable to preferred unitholders allocated to the general partner
                                  371,000 458,000 370,000 917,000                                                         
      basic income per common unit:
                                                                                              
      less: net income from continuing operations allocated to the general partner
                                  521,000 615,000 530,000                                                          
      less: net income allocated to the general partner
                                  521,000 614,000 521,000                                                          
      three months ended march 31, 2018
                                                                                              
      three months ended march 31, 2017
                                                                                              
      as of march 31, 2018
                                                                                              
      total assets of continuing operations
                                  943,334,000                                                            
      total assets of discontinued operations
                                                                                              
      as of december 31, 2017
                                                                                              
      basic income per unit:
                                                                                              
      diluted income per unit:
                                                                                              
      for the three months ended
                                                                                              
      september 30, 2017
                                                                                              
      september 30, 2016
                                                                                              
      less: fair value adjustments for warrant liabilities
                                     23,960,000                                                         
      less: net income from continuing operations and fair value adjustments for warrant liabilities allocated to the general partner
                                     586,000                                                         
      less: net income and fair value adjustments for warrant liabilities allocated to the general partner
                                     589,000                                                         
      june 30, 2017
                                                                                              
      june 30, 2016
                                                                                              
      less: other income from warrant liability fair value adjustments
                                      16,237,000                                                        
      plus: income attributable to preferred unitholders
                                      2,500,000                                                        
      march 31, 2017
                                                                                              
      march 31, 2016
                                                                                              
      total assets at march 31, 2017:
                                                                                              
      continuing operations
                                      956,782,000 3,814,000 16,155,000 47,726,000                                                     
      discontinued operations
                                       -317,000 6,970,000 -2,143,000                                                     
      total assets at december 31, 2016:
                                                                                              
      revenues and other income:
                                                                                              
      coal royalty and other—affiliates
                                       16,087,000 21,434,000                                                      
      vantacore
                                       32,721,000 31,757,000 31,642,000 24,682,000                                                    
      operating expenses:
                                                                                              
      operating and maintenance expenses—affiliates
                                       977,000 4,062,000 2,402,000 3,748,000                                                    
      amortization expense—affiliate
                                       857,000 902,000 704,000 722,000                                                    
      general and administrative—affiliates
                                       921,000 867,000 866,000 937,000 -6,153,000 4,144,000 3,535,000 3,786,000                                                
      other income
                                          -23,729,000   -23,342,000 -22,928,000                                                
      interest expense—affiliate
                                         -61,000                                                     
      interest income
                                       10,000 3,000 7,000 19,000 2,000  1,000 15,000 21,000 8,000 41,000 26,000 6,000 18,000 173,000 41,000 58,000 35,000 24,000 45,000 29,000 16,000 16,000 8,000 10,000 13,000 4,000 8,000 17,000 18,000 96,000 82,000 231,000 368,000 312,000 444,000 651,000 736,000 686,000 817,000 799,000 665,000 755,000 518,000 459,000 392,000 331,000 231,000  159,000 78,000 60,000 52,000   
      less: net loss attributable to non-controlling interest
                                            1,244,000                                                  
      net income attributable to limited partners:
                                                                                              
      total
                                       3,497,000 23,125,000 45,583,000                                                     
      net income attributable to the general partner:
                                                                                              
      basic and diluted net income per common unit:
                                                                                              
      weighted-average number of common units outstanding
                                        12,232,000 12,232,000 12,230,000 12,230,000 122,300,000 122,300,000 122,300,000 113,262,000    109,584,000    106,028,000                                       
      add: comprehensive loss from unconsolidated investment and other
                                       -173,000 -609,000                                                      
      less: comprehensive loss attributable to non-controlling interest
                                            1,244,000                                                  
      coal and hard mineral royalty and other
                                         58,892,000                                                     
      coal and hard mineral royalty and other—affiliates
                                         17,504,000                                                     
      oil and gas royalty
                                         1,091,000                                                     
      add: comprehensive income from unconsolidated investment and other
                                         462,000 -545,000 198,000 -1,136,000                                                  
      less: comprehensive income attributable to non-controlling interest
                                                                                              
      coal, hard mineral royalty and other
                                          28,476,000                                                    
      coal, hard mineral royalty and other—affiliates
                                          10,569,000                                                    
      net income attributable to partners:
                                                                                              
      limited partners
                                          23,024,000 -21,326,000 -586,013,000 30,707,000 17,139,000 8,472,000 35,450,000 30,779,000 31,953,000 46,041,000 35,403,000 40,244,000 46,948,000 58,905,000 50,961,000 48,939,000 50,283,000 -14,036,000 -28,700,000 51,305,000 44,376,000 41,656,000 39,350,000 28,054,000 16,864,000 27,391,000 25,161,000 4,804,000 21,598,000 36,012,000 35,505,000 30,562,000 25,853,000 22,142,000 22,902,000 18,145,000 17,779,000 19,301,000 21,483,000 21,848,000 25,608,000 23,066,000 19,999,000 23,464,000 19,390,000  12,762,000 18,646,000 14,685,000 10,915,000   
      general partner
                                          403,000 -460,000 -12,744,000 627,000 350,000 173,000 723,000 628,000 652,000 940,000 723,000 821,000 958,000 1,202,000 1,040,000 999,000 1,026,000 -286,000 -586,000 1,047,000 906,000 850,000 803,000 573,000 344,000 559,000 513,000 98,000 441,000 8,433,000 8,023,000 6,647,000 5,215,000 4,303,000 4,119,000 3,074,000 2,819,000 2,728,000 2,641,000 2,253,000 2,095,000 1,403,000 1,103,000 1,155,000 830,000  459,000 605,000 394,000 247,000   
      basic and diluted net income per common unit
                                          1,880 -41,350 -4,790 250 140                                                
      coal related revenues
                                           23,613,000 35,469,000 28,562,000 30,421,000 53,797,000 65,193,000 55,361,000 52,373,000                                            
      coal related revenues—affiliates
                                           17,734,500 19,535,000 32,342,000 19,061,000                                                
      aggregates related revenues
                                           28,539,500 42,326,000 42,886,000 28,946,000                                                
      oil and gas related revenues
                                           10,621,250 12,416,000 14,839,000 15,230,000 22,085,000 9,601,000 17,822,000 10,058,000                                            
      equity in earnings of unconsolidated investment
                                           9,184,750 12,617,000 11,599,000 12,523,000                                                
      other
                                           1,353,000 588,000 4,332,000 492,000 1,586,000 955,000 1,036,000 736,000 12,308,000 2,189,000 1,843,000 9,979,000 6,635,000 6,322,000 5,856,000 1,274,000 4,955,000 2,764,000 1,966,000 1,552,000 1,209,000 1,404,000 3,225,000 957,000 982,000 1,032,000 1,001,000 1,005,000 867,000 2,032,000 1,322,000 1,352,000 2,801,000 1,301,000 1,186,000 1,152,000 1,587,000 1,288,000 1,550,000 3,276,000 1,831,000 1,998,000 1,503,000 1,215,000  1,535,000 1,221,000 1,118,000 768,000   
      costs and expenses:
                                                                                              
      coal related expenses
                                           618,500 649,000 504,000 1,321,000                                                
      coal related expenses—affiliates
                                           10,250 -68,000 109,000                                                 
      aggregates related expenses
                                           21,578,500 31,107,000 32,800,000 22,407,000                                                
      oil and gas related expenses
                                           2,452,250 3,049,000 2,999,000 3,762,000                                                
      property, franchise and other taxes
                                           3,622,500 4,286,000 5,066,000 5,138,000 5,443,000 4,767,000 6,201,000 4,868,000 3,653,000 4,234,000 4,225,000 4,351,000 4,038,000 4,853,000 3,771,000 5,016,000 3,568,000 3,915,000 3,306,000 3,697,000 3,295,000 4,580,000 3,498,000 3,734,000 3,597,000 4,273,000 3,151,000 3,975,000 2,989,000 2,822,000 4,098,000 3,649,000 2,995,000 3,993,000 3,524,000 3,101,000 1,636,000 2,142,000 2,099,000 2,245,000 2,404,000 1,954,000 1,954,000         
      comprehensive (income) income from unconsolidated investment and other
                                             210,000                                                 
      comprehensive income attributable to non-controlling interest
                                             -1,244,000                                                 
      aggregate related revenues
                                               2,403,500 2,655,000 3,563,000 3,396,000                                            
      equity and other unconsolidated investment income
                                               12,551,000 9,685,000 9,401,000 9,779,000 12,018,000 7,238,000 7,882,000 7,048,000                                        
      oil and gas lease operating expenses
                                               2,785,000 2,147,000                                              
      transportation costs
                                               366,000 354,000 462,000 422,000 402,000 455,000 328,000 459,000 498,000 446,000 527,000 473,000 502,000 540,000 523,000 468,000 428,000 614,000 557,000 265,000 467,000 403,000 473,000 268,000 456,000 431,000 408,000 121,000 149,000 79,000 27,000 43,000                
      royalty payments
                                               846,250 3,029,000 201,000 155,000                                            
      income before non-controlling interest
                                               8,645,000 36,173,000 31,407,000 32,605,000 46,981,000 36,126,000 41,065,000 47,906,000 60,107,000 52,001,000 49,938,000 51,309,000 -13,375,000 -29,286,000 52,403,000 45,282,000 42,506,000 40,153,000 41,610,000                             
      non-controlling interest
                                                                                              
      net income attributable to:
                                                                                              
      basic and diluted net income per limited partner unit
                                               50 320 280 290 420 320 370 430 550 480   -130 -270 480 420 400 510 380 240 400 360 70 330 355 550 470 400                    
      weighted-average number of units outstanding
                                                111,244,000 110,403,000 109,848,000  109,812,000 109,812,000 108,887,000  106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 81,917,000 77,896,000 74,028,000 69,451,000 67,702,000 69,451,000 66,946,000 64,891,000  64,891,000 64,891,000 64,891,000                    
      oil and gas lease operating expense
                                                 2,291,000 1,921,000                                            
      coal royalties
                                                   47,706,000 52,305,000 58,210,000 54,442,000 67,681,000 70,259,000 62,878,000 59,916,000 67,638,000 76,430,000 69,788,000 65,365,000 56,626,000 60,142,000 57,832,000 47,161,000 48,327,000 49,307,000 46,380,000 52,607,000 58,749,000 58,323,000 60,026,000 49,152,000 45,259,000 44,378,000 40,733,000 40,973,000 35,213,000 36,902,000 36,527,000 39,110,000 37,383,000 34,267,000 37,957,000 32,530,000  27,114,000 30,315,000 26,179,000 22,848,000   
      aggregate royalties
                                                   1,774,000 2,566,000 1,751,000 1,552,000 1,537,000 1,643,000 1,702,000 1,716,000 1,610,000 2,099,000 1,831,000 1,194,000 1,383,000 1,606,000 350,000 891,000 883,000 1,700,000 1,347,000 1,650,000 1,544,000 2,280,000 1,933,000 3,362,000 1,649,000 2,096,000 1,944,000 1,745,000                
      processing fees
                                                   1,163,000 1,377,000 1,329,000 1,180,000 1,394,000 1,641,000 3,138,000 2,126,000                                    
      transportation fees
                                                   4,478,000 4,742,000 3,832,000 4,925,000 5,152,000 5,007,000 5,246,000 4,108,000 4,080,000 4,765,000 3,745,000 4,098,000 3,461,000 4,285,000 4,043,000 2,775,000 3,883,000 3,049,000 3,489,000 2,096,000 3,463,000 3,183,000 3,361,000 1,649,000 1,678,000 1,000,000 845,000 461,000                
      oil and gas royalties
                                                   2,435,500 3,886,000 4,093,000 1,763,000 2,448,000 1,246,000 4,078,000 1,388,000 3,970,000 5,059,000 1,996,000 2,992,000 3,520,000 1,013,000 2,087,000 1,099,000 3,871,000 1,203,000 953,000 1,493,000 2,323,000 2,201,000 1,933,000 1,445,000 1,006,000 1,388,000 1,278,000 1,258,000 720,000 853,000 928,000 1,719,000            
      minimums recognized as revenue
                                                   1,860,000 998,000 836,000 4,591,000 10,208,000 1,096,000 938,000 11,714,000 5,218,000 1,582,000 1,841,000 507,000 3,625,000 3,782,000 3,418,000 3,374,000 201,000 775,000 67,000 223,000 64,000 737,000 149,000 307,000 253,000 913,000 331,000 454,000 828,000 633,000 250,000 371,000 344,000 431,000 481,000 453,000  483,000 352,000 165,000 763,000   
      override royalties
                                                   2,488,000 2,927,000 3,179,000 4,905,000 3,529,000 3,359,000 3,497,000 5,142,000 3,857,000 4,131,000 3,492,000 3,043,000 2,509,000 2,625,000 3,157,000 2,967,000 3,290,000 2,077,000 1,336,000 2,548,000 3,689,000 3,133,000 2,006,000 2,499,000 800,000 953,000 1,023,000 1,018,000 190,000 283,000 181,000 303,000 833,000 487,000 209,000 615,000  832,000 956,000 757,000 677,000   
      lease operating expense
                                                   120,750 483,000                                          
      coal royalty and override payments
                                                   277,000 284,000 187,000 355,000 461,000 523,000 673,000 200,000 322,000 233,000 159,000 308,000 247,000 258,000 301,000 692,000 1,174,000 353,000 372,000 489,000 569,000 287,000 343,000 309,000 422,000 246,000 382,000 286,000 310,000 296,000 263,000 691,000 1,023,000 1,071,000 745,000 553,000  309,000 450,000     
      revenues:
                                                                                              
      total revenues
                                                     86,804,000 94,332,000 102,436,000 94,175,000 90,664,000 91,872,000 97,651,000 103,771,000 91,409,000 84,852,000 77,542,000 80,752,000 79,587,000 63,519,000 65,902,000 63,962,000 59,487,000 66,733,000 75,822,000 76,196,000 75,592,000 64,055,000 57,315,000 56,366,000 51,097,000 50,207,000 41,672,000 41,491,000 40,982,000 46,528,000 42,374,000 38,735,000 41,697,000 36,247,000  22,520,000 34,221,000 29,497,000 26,362,000   
      yoy
                                                     -4.26% 2.68% 4.90% -9.25% -0.82% 8.27% 25.93% 28.51% 14.85% 33.59% 17.66% 26.25% 33.79% -4.82% -13.08% -16.06% -21.31% 4.18% 32.29% 35.18% 47.94% 27.58% 37.54% 35.85% 24.68% 7.91% -1.66% 7.12% -1.71% 28.36%  72.00% 21.85% 22.88%        
      qoq
                                                     -7.98% -7.91% 8.77% 3.87% -1.31% -5.92% -5.90% 13.52% 7.73% 9.43% -3.98% 1.46% 25.30% -3.62% 3.03% 7.52% -10.86% -11.99% -0.49% 0.80% 18.01% 11.76% 1.68% 10.31% 1.77% 20.48% 0.44% 1.24% -11.92% 9.80% 9.39% -7.10% 15.04%   -34.19% 16.02% 11.89%    
      operating costs and expenses:
                                                                                              
      total operating costs and expenses
                                                       20,688,000 28,532,000 27,172,000 27,048,000 97,670,000 120,294,000 26,593,000 28,991,000 24,690,000 30,408,000 27,635,000 22,607,000 22,400,000 22,567,000 31,826,000 25,316,000 20,570,000 22,314,000 28,487,000 23,287,000 21,801,000 21,050,000 22,019,000 21,816,000 14,053,000 12,922,000 13,018,000 14,904,000 14,750,000 14,773,000 14,486,000 13,574,000  9,160,750 12,514,000 12,025,000 12,104,000   
      other income:
                                                                                              
      less non-controlling interest
                                                           -12,750  -51,000                                 
      coal processing fees
                                                           2,557,250 3,967,000 3,173,000 3,089,000 2,924,000 2,343,000 2,693,000 1,644,000 1,865,000 1,508,000 2,400,000 1,900,000 3,083,000 2,044,000 1,757,000 1,897,000 1,420,000 1,374,000 1,112,000 918,000                
      holders of incentive distribution rights
                                                                 12,983,000 12,983,000 4,977,000 4,977,000 12,180,000 11,381,000                     12,000   
      other holders of incentive distribution rights
                                                                       2,434,500 3,810,000 3,144,000 2,784,000 1,150,500 1,907,000 1,412,000 1,283,000 728,500 1,150,000 943,000 821,000 235,750 363,000 353,000 227,000  103,000 117,000 49,000    
      basic and diluted net income per limited partner unit:
                                                                                              
      common
                                                                           350 350 280 280 760 850 860 1,010 910 790 920 770  500 740 580 470   
      subordinated
                                                                           350 350 280 280 760 850 860 1,010 910 790 920 770  500 740 580 470   
      weighted-average number of units outstanding:
                                                                                              
      class b
                                                                             280 280                
      depletion and amortization
                                                                                   6,181,250 8,221,000 8,625,000 7,879,000  8,039,000 8,077,000 7,493,000 7,348,000   
      taxes other than income
                                                                                      1,830,000  2,002,000 1,464,000 1,712,000 1,657,000   
      loss from interest rate hedge
                                                                                              
      override payments
                                                                                              
      coal royalty payments
                                                                                          398,000 388,000   
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 2018-12-31 2018-09-30 2018-06-30 2018-03-31 2017-12-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 2013-12-31 2013-09-30 2013-06-30 2013-03-31 2012-12-31 2012-09-30 2012-06-30 2012-03-31 2011-12-31 2011-09-30 2011-06-30 2011-03-31 2010-12-31 2010-09-30 2010-03-31 2009-12-31 2009-09-30 2009-06-30 2009-03-31 2008-06-30 2008-03-31 2007-09-30 2007-06-30 2007-03-31 2006-09-30 2006-06-30 2006-03-31 2005-09-30 2005-06-30 2005-03-31 2004-12-31 2004-09-30 2004-06-30 2004-03-31 2003-12-31 
                                                                                       
        assets
                                                                                       
        current assets
                                                                                       
        cash and cash equivalents
      31,019,000 30,344,000 30,876,000 30,444,000 30,900,000 32,340,000 10,990,000 11,989,000 18,411,000 10,730,000 17,655,000 39,091,000 60,937,000 59,356,000 135,590,000 135,520,000 118,989,000 97,908,000 96,767,000 99,790,000 115,573,000 110,828,000 100,506,000 98,265,000 99,636,000 70,850,000 112,374,000 101,839,000 63,387,000 52,975,000 21,152,000 29,827,000 121,244,000 40,783,000 112,945,000 40,371,000 92,391,000 21,391,000 51,773,000 61,156,000 27,525,000 33,275,000 50,076,000 78,126,000 70,013,000 54,826,000 92,513,000 99,675,000 105,204,000 76,153,000 149,424,000 122,419,000 121,974,000 107,404,000 214,922,000 150,112,000 145,705,000 69,008,000 95,506,000 72,240,000 62,856,000 82,634,000 60,880,000 81,495,000 101,109,000 60,454,000 54,320,000 54,377,000 54,454,000 55,617,000 60,784,000 52,620,000 67,368,000 49,457,000 50,760,000 47,103,000 42,103,000 36,286,000 21,559,000 29,996,000 24,320,000 
        accounts receivable
      30,442,000 29,048,000 31,387,000 31,469,000 36,886,000 30,624,000 33,874,000 41,086,000 38,569,000 37,120,000 36,513,000 42,701,000 34,726,000 37,288,000 32,729,000 24,538,000 23,231,000 15,322,000 15,920,000 12,322,000 17,462,000 22,044,000 34,113,000 30,869,000 27,447,000 28,553,000 37,023,000 32,024,000 55,734,000 59,312,000 55,651,000 47,026,000 48,788,000 53,997,000 44,470,000 43,202,000 44,139,000 40,815,000 50,167,000 54,888,000 54,230,000 52,323,000 66,455,000 33,954,000 34,718,000 38,506,000 33,737,000 30,639,000 29,995,000 34,591,000 35,116,000 36,761,000 33,029,000 34,075,000 30,923,000 34,538,000 31,728,000 32,041,000 26,195,000 28,974,000 28,268,000 27,141,000 29,873,000 26,293,000 34,626,000 32,851,000 30,785,000 30,003,000 25,607,000 27,113,000 24,332,000 22,051,000 21,956,000 18,099,000 18,446,000 17,473,000 15,058,000 14,472,000 14,198,000 12,934,000 9,553,000 
        other current assets
      455,000 1,329,000 2,137,000 1,961,000 1,483,000 3,114,000 3,494,000 2,218,000 2,570,000 2,865,000 3,216,000 1,822,000 1,228,000 3,204,000 3,510,000 2,723,000 1,010,000 4,038,000 3,021,000 5,080,000 3,972,000                                                             
        total current assets
      61,916,000 60,721,000 64,400,000 63,874,000 69,269,000 66,078,000 48,358,000 55,293,000 59,550,000 50,715,000 57,384,000 83,614,000 96,891,000 99,848,000 171,829,000 162,781,000 143,230,000 117,268,000 115,708,000 117,192,000 137,007,000 137,803,000 135,785,000 132,084,000 143,709,000 121,275,000 171,869,000 242,543,000 134,368,000 125,854,000 89,047,000 91,396,000 186,462,000 107,096,000 195,257,000 104,252,000 160,965,000 196,649,000 121,129,000 133,004,000 99,927,000 101,393,000 136,118,000 123,526,000 115,040,000 105,681,000 135,607,000 139,145,000 152,893,000 124,524,000 196,195,000 169,475,000 168,426,000 155,151,000 256,815,000 197,383,000 182,584,000 108,391,000 130,526,000 109,261,000 97,229,000 115,047,000 93,218,000 112,398,000 138,474,000 104,804,000 93,713,000 91,866,000 87,459,000 90,100,000 85,482,000 75,269,000 89,889,000 67,598,000 69,497,000 65,112,000  50,796,000 36,222,000 43,749,000  
        land
      24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,008,000 24,809,000 24,809,000 24,809,000 25,247,000 25,261,000 25,272,000 12,591,000 25,252,000 25,020,000 25,020,000 25,022,000 25,022,000 25,243,000 25,243,000 25,243,000 24,338,000 24,340,000 24,340,000 24,340,000 24,340,000 24,340,000 24,340,000 24,340,000 24,515,000 24,515,000 24,534,000 24,534,000 24,533,000 24,543,000 24,543,000 24,543,000 24,343,000 24,343,000 24,343,000 24,343,000 24,343,000 24,343,000 24,343,000 24,343,000 24,532,000 24,522,000 24,522,000 12,461,000 12,436,000 12,731,000 14,110,000 14,110,000 14,110,000 13,721,000 13,721,000 13,721,000 13,532,000 13,532,000 
        mineral rights
      369,902,000 373,717,000 377,245,000 379,638,000 382,274,000 387,053,000 390,176,000 394,483,000 400,548,000 404,741,000 408,371,000 412,312,000 421,351,000 428,505,000 433,965,000 437,697,000 442,454,000 447,155,000 451,610,000 460,373,000 465,870,000 468,863,000 603,208,000 605,096,000 733,154,000 736,413,000 739,570,000 743,112,000 869,106,000 873,716,000 878,845,000 883,885,000 890,610,000 895,642,000 895,071,000 908,192,000 924,181,000 946,355,000 1,094,027,000 1,144,809,000 1,788,454,000 1,773,449,000 1,781,852,000 1,385,919,000 1,391,439,000 1,395,321,000 1,405,455,000 1,382,864,000 1,360,386,000 1,375,972,000 1,380,428,000                               
        intangible assets
      12,332,000 12,381,000 12,602,000 12,924,000 13,109,000 13,143,000 13,340,000 13,682,000 14,014,000 14,432,000 14,613,000 14,713,000 15,168,000 15,634,000 16,019,000 16,130,000 16,243,000 16,742,000 17,131,000 17,459,000 17,601,000 17,608,000 17,607,000 17,687,000 40,461,000 41,008,000 41,754,000 42,513,000 46,998,000 47,924,000 48,769,000 49,554,000 50,370,000 51,226,000 3,065,000 3,236,000 3,239,000 3,470,000 56,927,000 58,269,000 59,182,000 59,713,000 60,733,000 58,696,000 59,549,000 66,102,000 66,950,000 68,110,000 69,064,000 69,808,000 70,811,000 71,900,000 72,972,000 74,209,000 75,164,000 109,885,000 156,775,000 159,281,000 161,931,000 160,751,000 163,794,000 165,160,000 162,779,000 163,610,000 131,993,000 104,691,000 105,674,000 111,179,000 111,511,000 107,027,000            
        equity in unconsolidated investment
      253,717,000 258,498,000 261,286,000 257,355,000 267,806,000 265,935,000 268,634,000 276,549,000 282,491,000 290,900,000 295,361,000 306,470,000 284,806,000 280,300,000 280,156,000 276,004,000 277,309,000 266,433,000 261,299,000 262,514,000 256,834,000 252,420,000 261,224,000 263,080,000 258,063,000 251,135,000 249,936,000 247,051,000 242,901,000 245,524,000 241,679,000 245,433,000 245,382,000 248,919,000 252,803,000 255,901,000 257,661,000 259,778,000 261,942,000 262,347,000 263,619,000 262,722,000                                        
        long-term contract receivable
      21,197,000 21,973,000 22,734,000 23,480,000 24,212,000 24,929,000 25,632,000 26,321,000 26,997,000 27,659,000 28,309,000 28,946,000 29,570,000 30,182,000 30,783,000 31,371,000 31,948,000 32,514,000 32,726,000 33,264,000 33,791,000 34,309,000 34,816,000 36,963,000 37,473,000                                                         
        other long-term assets
      10,482,000 10,668,000 10,198,000 11,628,000 9,187,000 8,412,000 8,034,000 7,540,000 7,601,000 7,804,000 7,622,000 7,068,000 7,216,000 4,664,000 5,528,000 5,832,000 5,814,000 6,085,000 6,678,000 7,067,000 7,447,000                                                             
        total assets
      753,554,000 761,966,000 772,473,000 772,907,000 789,865,000 789,558,000 778,182,000 797,876,000 815,209,000 820,259,000 835,668,000 877,131,000 879,010,000 883,141,000 962,288,000 953,823,000 941,006,000 910,205,000 909,160,000 921,877,000 942,558,000 943,565,000 1,083,422,000 1,085,907,000 1,243,904,000 1,219,443,000 1,272,171,000 1,341,647,000 1,411,934,000 1,411,806,000 1,377,206,000 1,389,164,000 1,495,513,000 1,429,052,000 1,509,250,000 1,444,681,000 1,521,406,000 1,585,086,000 1,684,075,000 1,766,394,000 2,385,105,000 2,393,925,000 2,444,724,000 1,938,544,000 1,938,808,000 1,946,643,000 1,991,856,000 1,950,635,000 1,975,851,000 1,985,371,000 1,764,672,000 1,713,678,000 1,694,360,000 1,671,874,000 1,665,649,000 1,676,264,000 1,792,700,000 1,718,295,000 1,664,036,000 1,603,002,000 1,544,833,000 1,523,590,000 1,510,123,000 1,508,085,000 1,459,228,000 1,305,937,000 1,307,104,000 1,297,335,000 1,298,685,000 1,288,096,000 781,368,000 723,846,000 729,713,000 661,196,000 618,273,000 622,690,000  600,856,000 593,957,000 607,297,000  
        liabilities and capital
                                                                                       
        current liabilities
                                                                                       
        accounts payable
      886,000 930,000 1,455,000 909,000 984,000 933,000 1,514,000 885,000 1,143,000 1,524,000 1,452,000 1,992,000 2,179,000 1,969,000 1,896,000 1,956,000 1,474,000 1,293,000 1,375,000 1,385,000 1,372,000 1,228,000 1,272,000 1,179,000 1,591,000 1,211,000 1,797,000 548,000 7,467,000 7,801,000 5,911,000 6,957,000 5,812,000 5,257,000 6,538,000 6,234,000 6,223,000 5,260,000 8,465,000 11,377,000 16,692,000 16,862,000                             817,000 659,000 715,000 681,000 479,000 304,000 576,000 317,000 195,000 401,000 423,000 
        accrued liabilities
      8,313,000 7,649,000 5,098,000 12,121,000 7,912,000 7,225,000 5,064,000 12,987,000 6,511,000 5,715,000 3,466,000 11,916,000 5,913,000 5,507,000 3,388,000 10,297,000 6,228,000 5,746,000 4,853,000 7,733,000 6,859,000 6,027,000 6,004,000 8,764,000 7,290,000 6,856,000 6,200,000 12,347,000 14,005,000 12,848,000 11,409,000 16,890,000 28,659,000 37,213,000 33,509,000 41,587,000 44,816,000 33,837,000 45,735,000 54,895,000 45,924,000 50,772,000                                        
        accrued interest
      492,000 169,000 556,000 302,000 775,000 319,000 995,000 584,000 1,224,000 625,000 1,252,000 989,000 4,227,000 1,050,000 8,463,000 1,213,000 8,685,000 1,423,000 8,847,000 1,714,000 9,273,000 2,026,000 9,376,000 2,316,000 14,364,000 7,201,000 4,312,000 14,345,000 5,540,000 14,609,000 5,706,000 15,484,000           18,216,000 20,376,000 15,412,000 21,557,000 17,184,000 7,667,000 9,689,000 8,340,000 10,265,000 7,990,000 10,603,000 7,866,000 10,761,000 8,101,000 11,679,000 2,777,000 9,811,000 2,842,000 3,164,000 10,300,000 3,362,000 10,328,000 3,274,000 6,011,000 3,356,000 3,680,000 6,443,000 3,412,000 3,771,000 2,751,000 3,440,000 2,820,000 435,000 2,513,000 266,000 2,447,000 267,000 2,697,000 681,000 
        current portion of deferred revenue
      5,005,000 4,667,000 4,949,000 4,341,000 5,823,000 4,449,000 5,635,000 4,599,000 6,399,000 6,823,000 7,450,000 6,256,000 8,886,000 11,475,000 15,420,000 11,817,000 11,201,000 10,293,000 10,555,000 11,485,000 11,035,000 8,857,000 6,021,000 4,608,000 5,047,000 6,579,000 4,614,000 3,509,000 1,403,000 2,732,000 1,554,000                                                   
        current portion of long-term debt
      14,246,000 14,228,000 14,210,000 14,192,000 14,226,000 14,214,000 14,202,000 30,785,000 36,780,000 36,743,000 39,055,000 39,076,000 89,989,000 39,070,000 39,046,000 39,102,000 39,082,000 39,060,000 39,042,000 39,055,000 39,072,000 45,786,000 45,767,000 45,776,000 45,789,000 46,040,000 46,024,000 115,184,000 75,201,000 75,188,000 79,723,000 79,740,000 174,138,000 173,901,000 263,502,000 138,903,000 158,597,000 157,996,000 80,983,000 80,983,000 155,983,000 155,983,000 80,983,000 80,983,000 80,983,000 80,983,000 80,983,000 56,175,000 59,175,000 58,858,000 87,230,000 87,230,000 87,230,000 52,230,000 30,801,000 30,801,000 30,801,000 31,518,000 31,518,000 31,518,000 32,235,000 32,235,000 32,235,000 32,235,000 32,235,000 17,234,000 17,234,000 17,234,000 9,542,000 9,542,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 9,350,000 
        total current liabilities
      28,942,000 27,643,000 26,268,000 31,865,000 29,720,000 27,140,000 27,410,000 49,840,000 52,057,000 51,430,000 52,675,000 60,229,000 111,194,000 59,071,000 68,213,000 64,385,000 66,670,000 57,815,000 64,672,000 61,372,000 67,611,000 63,924,000 68,440,000 62,708,000 74,255,000 68,545,000 63,674,000 148,746,000 104,224,000 114,631,000 106,399,000 120,549,000 209,737,000 217,411,000 305,049,000 188,017,000 211,300,000 277,819,000 136,647,000 149,821,000 219,538,000 224,553,000 147,931,000 128,050,000 122,466,000 125,392,000 123,388,000 83,249,000 87,384,000 82,764,000 117,815,000 112,203,000 113,852,000 74,813,000 59,493,000 53,691,000 59,939,000 51,033,000 56,930,000 48,361,000 49,699,000 57,388,000 57,248,000 52,067,000 63,508,000 37,005,000 30,505,000 32,726,000 27,542,000 25,433,000 23,438,000 21,442,000 22,395,000 17,948,000 14,717,000 17,140,000  16,531,000 13,859,000 16,511,000  
        deferred revenue
      52,514,000 51,275,000 51,979,000 55,814,000 53,912,000 40,433,000 38,348,000 38,356,000 35,076,000 36,815,000 38,833,000 40,181,000 35,882,000 40,811,000 39,126,000 50,045,000 48,232,000 51,793,000 50,853,000 50,069,000 50,980,000 53,431,000 54,065,000 47,213,000 43,587,000 43,290,000 52,473,000 49,044,000 40,885,000 17,136,000 14,622,000 100,605,000 106,391,000 110,885,000 46,008,000 44,931,000 40,050,000 42,608,000 80,812,000 79,242,000 80,706,000 79,052,000 160,260,000 153,931,000 149,685,000 146,328,000 142,586,000 136,677,000 133,297,000 127,894,000 123,506,000 123,689,000 118,373,000 109,373,000 113,303,000 108,093,000 122,707,000 114,943,000 109,509,000 96,272,000 80,031,000 67,018,000 51,060,000 49,064,000 46,266,000 39,012,000 38,699,000 31,461,000 28,571,000 24,555,000 15,884,000 15,259,000 14,219,000 13,795,000 15,498,000 15,710,000 15,847,000 13,144,000 13,262,000 15,122,000 15,054,000 
        long-term debt
      55,131,000 87,112,000 124,594,000 127,876,000 183,137,000 196,112,000 174,595,000 124,273,000 170,735,000 145,693,000 133,821,000 129,205,000 148,734,000 259,296,000 378,163,000 394,443,000 414,437,000 414,099,000 416,121,000 432,444,000 452,401,000 452,101,000 454,110,000 470,422,000 490,378,000 498,029,000 541,677,000 557,574,000 716,514,000 723,147,000 724,854,000 729,608,000 762,441,000 700,252,000 707,424,000 987,400,000 1,041,984,000 1,050,562,000 1,284,083,000 1,323,708,000 1,256,218,000 1,283,352,000 1,394,240,000 1,017,498,000 1,033,041,000 1,045,209,000 1,084,226,000 1,088,884,000 1,088,556,000 1,088,789,000 897,039,000 852,039,000 829,731,000 846,648,000 836,268,000 786,268,000 793,961,000 730,877,000 661,070,000 606,070,000 657,395,000 626,587,000 620,587,000 606,280,000 615,630,000 486,514,000 495,864,000 473,057,000 474,149,000 465,099,000 300,600,000 247,600,000 256,950,000 202,950,000 164,950,000 174,300,000 156,300,000 156,300,000 156,300,000 165,650,000 192,650,000 
        other non-current liabilities
      5,717,000 5,491,000 5,275,000 6,244,000 5,903,000 6,619,000 6,305,000 7,172,000 6,833,000 6,462,000 6,124,000 5,472,000 5,231,000 5,012,000 4,803,000 5,018,000 4,920,000 4,819,000 4,730,000 5,131,000 5,020,000 4,901,000 4,804,000 4,949,000 4,843,000 4,731,000 4,720,000 1,150,000 1,958,000 2,385,000 2,492,000 2,808,000 2,727,000 2,699,000 3,102,000 4,565,000 4,404,000 3,670,000 6,808,000 9,839,000 9,797,000 8,403,000 10,679,000 9,712,000 9,712,000 9,609,000 14,341,000                                   
        total liabilities
      142,304,000 171,521,000 208,116,000 221,799,000 272,672,000 270,304,000 246,658,000 219,641,000 264,701,000 240,400,000 231,453,000 235,087,000 301,041,000 364,190,000 490,305,000 513,891,000 534,259,000 528,526,000 536,376,000 549,016,000 576,012,000 574,357,000 581,419,000 585,292,000 613,063,000 614,595,000 662,544,000 756,514,000 863,581,000 857,299,000 848,367,000 953,916,000 1,081,296,000 1,068,704,000 1,191,735,000                                               
        commitments and contingencies
                                                                                       
        partners’ capital
                                                                                       
        common unitholders’ interest
      602,552,000 579,773,000 553,754,000 543,231,000 509,258,000 490,877,000 474,095,000 503,076,000 461,043,000 444,838,000 417,401,000 404,799,000 358,332,000 300,753,000 250,767,000 203,062,000 151,459,000 134,836,000 132,377,000 136,927,000 134,545,000 139,517,000 273,847,000 271,471,000 400,266,000 374,275,000 378,140,000 355,113,000 319,673,000 326,125,000 301,344,000 199,851,000 182,760,000 204,230,000 163,304,000 152,309,000 154,315,000 136,695,000 79,094,000 106,011,000 703,055,000 683,354,000                                        
        general partner’s interest
      10,913,000 10,496,000 10,013,000 9,547,000 8,891,000 8,568,000 7,721,000 8,005,000 7,196,000 6,913,000 6,400,000 5,977,000 5,054,000 3,904,000 2,909,000 1,787,000 754,000 434,000 394,000 459,000 428,000 546,000 3,305,000 3,270,000 5,909,000 5,387,000 5,476,000 5,014,000 4,293,000 4,427,000 3,924,000 1,857,000 1,508,000 1,946,000 1,111,000 887,000 928,000 568,000 -606,000 -60,000 12,122,000 11,721,000 12,245,000 10,212,000 10,124,000 10,050,000 10,069,000 10,362,000 10,872,000 11,283,000 10,026,000 10,013,000 10,162,000 10,354,000 10,517,000 11,995,000 13,750,000 13,868,000 14,132,000 14,450,000 12,886,000 13,409,000 13,717,000 14,218,000 13,086,000 13,658,000        9,653,000 9,439,000       
        accumulated other comprehensive loss
      -2,215,000   -1,670,000 -956,000 -1,038,000 -2,277,000               -2,258,000 -3,617,000 -2,594,000 -3,802,000 -3,282,000 -2,457,000 -3,462,000 -4,081,000 -4,872,000 -4,438,000 -3,313,000 -3,079,000 -2,811,000 -2,798,000 -1,666,000 -2,844,000 -2,235,000 -2,152,000 -2,350,000 -1,214,000 -1,424,000 -459,000 -272,000 -642,000 -479,000 -378,000 -297,000 -338,000 -389,000 -443,000 -456,000 -470,000 -483,000 -493,000 -507,000 -521,000 -534,000 -546,000 -560,000 -584,000 -597,000 -610,000 -623,000 -636,000 -673,000 -686,000 -712,000 -725,000 -738,000 -763,000 -776,000 -789,000 -815,000 -828,000 -841,000 -853,000 -864,000 -878,000 -891,000 -905,000 
        total partners’ capital
      611,250,000 590,445,000 564,357,000  517,193,000 498,407,000 484,343,000  503,327,000 499,760,000 470,899,000  413,382,000 354,364,000 307,396,000  226,820,000 205,673,000 200,641,000 204,524,000 201,959,000 204,621,000 340,351,000 338,963,000 469,189,000 443,196,000 447,975,000 423,481,000 386,701,000 392,496,000 367,646,000 265,211,000 248,005,000 203,365,000 161,617,000 151,530,000 152,399,000 135,028,000 76,336,000 103,601,000 713,963,000 693,651,000 720,155,000 622,466,000 617,833,000 614,632,000 616,789,000 632,844,000 658,306,000 678,833,000 617,447,000 616,832,000 624,603,000 634,157,000 644,915,000 717,781,000 805,532,000 812,019,000 825,180,000 843,610,000 752,082,000 765,226,000 775,634,000 795,667,000 730,053,000 737,062,000 738,225,000 754,453,000 763,147,000 769,392,000 437,766,000 436,298,000 433,540,000 421,001,000 418,739,000 412,125,000  412,636,000 408,917,000 408,760,000  
        total liabilities and partners' capital
      753,554,000 761,966,000 772,473,000 772,907,000 789,865,000 789,558,000 778,182,000 797,876,000 815,209,000 820,259,000 835,668,000 877,131,000 879,010,000 883,141,000 962,288,000 953,823,000 941,006,000 910,205,000 909,160,000                                                               
        revenues and other income
                                                                                       
        royalty and other mineral rights
      49,615,000 44,295,000 51,260,000  50,405,000 54,591,000 67,372,000  68,533,000 61,007,000 76,271,000  81,379,000 79,333,000 71,083,000 185,196,000                                                                  
        transportation and processing services
      1,800,000 2,551,000 4,421,000  1,812,000 2,661,000 3,427,000  4,579,000 3,270,000 3,598,000  5,969,000 5,612,000 3,796,000 9,052,000 2,171,000 2,182,000 2,192,000 8,845,000 2,204,000 1,938,000 2,509,000 19,279,000 3,865,000 5,274,000 5,601,000 23,887,000 6,853,000 5,002,000 5,383,000                                                   
        equity in earnings of sisecam wyoming
      -2,390,000 2,526,000 4,610,000  8,109,000 3,645,000 5,450,000  12,401,000 26,978,000 19,254,000  14,556,000 14,643,000 14,837,000 21,871,000                                                                  
        gain on asset sales and disposals
      906,000 729,000 247,000  1,000 4,643,000 165,000  854,000 5,000 96,000  354,000 345,000  245,000 68,000 116,000 59,000 581,000  465,000  6,498,000 6,107,000                                                         
        total revenues and other income
      49,931,000 50,101,000 60,538,000  60,327,000 65,540,000 76,414,000  86,367,000 91,260,000 99,219,000  102,258,000 99,933,000 89,716,000 216,364,000 56,795,000 38,510,000 37,151,000 140,320,000 29,930,000 31,011,000 40,214,000 263,935,000 63,709,000 81,469,000 67,041,000 278,512,000 95,018,000 111,049,000 89,026,000 378,017,000 93,287,000 94,931,000 88,697,000 400,059,000 97,874,000 118,246,000 488,849,000 125,479,000 137,630,000 109,677,000 399,752,000 91,609,000 90,561,000 80,309,000 358,117,000 82,237,000                                  
        operating expenses
                                                                                       
        operating and maintenance expenses
      7,654,000 4,159,000 6,776,000  6,786,000 5,872,000 5,733,000  8,358,000 7,930,000 7,163,000  7,898,000 10,015,000 8,076,000 27,049,000 8,354,000 5,170,000 5,552,000 24,795,000 5,781,000 8,217,000 5,202,000 32,738,000 5,994,000 12,459,000 8,360,000 17,894,000 35,134,000 38,301,000 29,968,000 126,982,000 32,441,000 31,020,000 29,628,000 119,621,000 31,242,000 29,797,000 155,959,000                                           
        depreciation, depletion and amortization
      3,868,000 3,754,000 3,989,000  4,730,000 3,324,000 4,654,000  4,594,000 3,792,000 4,083,000  6,850,000 5,847,000 3,868,000 19,075,000 5,182,000 4,871,000 5,092,000 9,198,000 2,111,000 2,062,000 2,012,000 14,932,000 3,384,000 3,970,000 4,392,000 21,689,000 8,221,000 8,563,000 7,957,000 34,985,000 8,306,000 8,165,000 9,724,000 43,087,000 11,929,000 10,472,000 100,828,000 26,624,000 30,660,000 25,392,000 79,876,000 18,621,000 16,350,000 14,647,000 64,377,000 17,852,000 17,411,000 14,762,000 58,221,000 14,485,000 15,172,000 12,409,000 65,118,000 19,153,000 16,166,000 14,322,000 56,978,000 16,195,000 11,368,000 60,012,000 12,952,000 21,996,000 13,078,000 16,748,000 15,059,000 13,045,000 12,527,000 11,752,000 7,009,000 7,236,000 7,853,000         
        general and administrative expenses
      5,725,000 5,597,000 6,832,000  5,935,000 5,931,000 6,327,000  5,669,000 5,643,000 5,845,000  4,518,000 5,052,000 4,467,000 17,360,000 4,052,000 3,388,000 4,110,000 14,293,000 3,634,000 3,621,000 3,913,000 16,730,000 4,253,000 4,196,000 4,350,000                                                       
        asset impairments
        20,000  87,000    63,000 69,000   812,000 43,000 19,000 5,102,000 57,000 16,000 4,043,000 135,885,000 934,000 132,283,000  148,214,000 484,000   18,280,000   242,000 3,031,000   1,778,000 16,926,000 5,697,000 91,000 681,594,000 626,838,000 3,803,000  26,209,000  5,624,000  734,000  443,000 291,000 2,568,000    161,336,000                           
        total operating expenses
      17,247,000 13,510,000 17,617,000  17,538,000 15,127,000 16,714,000  18,684,000 17,434,000 17,091,000  20,078,000 20,957,000 16,430,000 68,586,000 17,645,000 13,445,000 18,797,000 184,171,000 12,460,000 146,183,000 11,127,000 212,614,000 14,115,000 20,625,000 17,102,000 85,974,000 48,952,000 54,192,000 44,968,000 194,042,000 46,756,000 44,527,000 51,655,000 214,314,000 58,967,000 47,505,000 966,760,000 701,769,000 81,710,000 69,260,000 210,833,000 36,582,000 40,158,000 27,870,000 121,881,000 30,613,000 31,472,000 31,804,000 111,982,000                               
        income from operations
      32,684,000 36,591,000 42,921,000  42,789,000 50,413,000 59,700,000  67,683,000 73,826,000 82,128,000  82,180,000 78,976,000 73,286,000 147,778,000 39,150,000 25,065,000 18,354,000 -43,851,000 17,470,000 -115,172,000 29,087,000 51,321,000 49,594,000 60,844,000 49,939,000 192,538,000 46,066,000 56,857,000 44,058,000 183,975,000 46,531,000 50,404,000 37,042,000 185,745,000 38,907,000 70,741,000 -477,911,000 -576,290,000 55,920,000 40,417,000 188,919,000 55,027,000 50,403,000 52,439,000 236,236,000 51,624,000 55,332,000 62,528,000 267,165,000 65,643,000 63,492,000 64,824,000 104,135,000 -16,523,000 64,816,000 55,861,000 196,061,000 50,344,000 40,912,000 153,975,000 41,395,000 27,661,000 41,417,000 47,105,000 40,768,000 35,316,000 29,078,000 28,391,000 28,569,000 27,964,000 31,624,000 23,962,000 27,211,000 22,673,000 70,092,000 21,707,000 17,472,000 14,258,000 44,069,000 
        interest expense
      -1,779,000 -2,380,000 -2,668,000  -4,194,000 -4,349,000 -3,487,000  -3,837,000 -3,492,000 -2,853,000  -5,141,000 -8,108,000 -9,387,000 -38,876,000 -9,652,000 -9,683,000 -9,973,000 -40,968,000 -10,254,000 -10,329,000 -10,308,000 -47,453,000 -10,431,000 -12,456,000 -14,174,000 -70,178,000 -17,501,000 -17,734,000 -18,006,000 -82,902,000 -20,080,000 -20,377,000 -23,141,000 -90,047,000 -22,491,000 -22,054,000 -93,827,000 -23,711,000 -23,343,000 -22,943,000 -80,185,000 -18,862,000 -19,037,000 -19,860,000 -64,396,000 -15,516,000 -14,440,000 -14,663,000 -53,972,000 -13,677,000 -13,578,000 -13,560,000 -49,180,000 -12,779,000 -12,429,000 -10,587,000 -41,635,000 -10,204,000 -10,729,000 -40,108,000 -10,762,000 -10,675,000 -8,079,000 -7,064,000 -7,360,000 -7,124,000 -7,133,000 -7,327,000 -3,960,000 -3,675,000 -3,618,000 -2,889,000 -2,570,000 -2,457,000 -10,312,000 -2,417,000 -2,404,000 -3,136,000  
        net income
      30,905,000 34,211,000 40,253,000  38,595,000 46,064,000 56,213,000  63,846,000 70,334,000 79,275,000  74,555,000 66,820,000 63,899,000 108,902,000 29,498,000 15,382,000 8,381,000 -84,819,000 7,216,000 -125,501,000 18,779,000 -24,458,000 39,170,000 19,351,000 35,719,000 140,047,000 28,541,000 39,089,000 26,074,000 88,667,000 26,066,000 49,950,000 16,764,000 96,892,000 23,531,000 46,446,000 -571,720,000 -600,001,000 32,578,000 17,489,000 108,830,000 36,173,000 31,407,000 32,605,000 172,078,000 36,126,000 41,065,000 47,906,000 213,355,000 52,001,000 49,938,000 51,309,000 54,026,000 -29,286,000 52,352,000 45,282,000 154,461,000 40,153,000 30,191,000 114,080,000 30,651,000 17,082,000 33,420,000 40,353,000 33,852,000 28,928,000 22,631,000 21,881,000 25,274,000 25,044,000 28,524,000 21,465,000 24,972,000 20,447,000 58,994,000 19,368,000 15,128,000 11,174,000 36,907,000 
        less: income attributable to preferred unitholders
          -655,000 -1,443,000 -2,150,000  -2,936,000 -4,971,000 -6,661,000  -7,500,000 -7,500,000 -7,500,000 -31,609,000 -7,961,000 -7,842,000 -7,727,000 -30,225,000 -7,500,000 -7,613,000 -7,500,000 -30,000,000 -7,500,000 -7,500,000 -7,500,000 -30,000,000 -7,500,000 -7,500,000 -7,500,000 -25,453,000 -7,650,000 -7,538,000 -2,500,000                                               
        less: redemption of preferred units
          -10,819,000 -13,666,000   -17,083,000 -27,618,000 -16,228,000                                                                       
        net income attributable to common unitholders and the general partner
      30,905,000 34,211,000 40,253,000  27,121,000 30,955,000 54,063,000  43,827,000 37,745,000 56,386,000  67,055,000 59,320,000 56,399,000 77,293,000 21,537,000 7,540,000 654,000 -115,044,000                                                              
        net income attributable to common unitholders
      30,287,000 33,527,000 39,448,000  26,578,000 30,336,000 52,982,000  42,951,000 36,990,000 55,258,000  65,714,000 58,134,000 55,271,000 75,747,000 21,106,000 7,389,000 641,000 -112,743,000 -279,000 -130,452,000 11,053,000 -53,369,000 31,036,000 11,614,000 27,655,000 107,346,000 20,972,000 30,105,000 18,203,000 61,950,000                                                  
        net income attributable to the general partner
      618,000 684,000 805,000  543,000 619,000 1,081,000  876,000 755,000 1,128,000  1,341,000 1,186,000 1,128,000 1,546,000 431,000 151,000 13,000 -2,301,000 -5,000 -2,662,000 226,000 -1,089,000 634,000 237,000 564,000 2,191,000 428,000 615,000 371,000 1,264,000                                                  
        net income per common unit
                                                                                       
        basic
      2,310 2,550 3,010  2,040 2,330 4,130  3,400 2,930 4,400  5,250 4,650 4,450 6,140 1,710 600 50 -9,200 -20 -10,640 900 -4,430 2,530 930 2,260 7,350 1,710 2,460 1,490 5,110 1,510 3,380 1,170                                               
        diluted
      2,280 2,520 2,970  2,000 2,290 3,830  2,910 2,490 3,440  3,710 3,290 3,110 4,810 1,100 560 50 -9,200 -20 -10,640 520 -4,430 1,660 850 1,750 5,900 1,300 1,750 1,160 3,980 1,080 1,130 30                                               
        comprehensive income from unconsolidated investment and other
      -2,391,000 -414,000 2,260,000  82,000 1,239,000 845,000  2,200,000 911,000 -19,583,000  289,000 -4,013,000 2,545,000 2,889,000 4,204,000 2,533,000 732,000 2,916,000 2,428,000 1,359,000 -1,023,000 868,000 -520,000 -825,000 1,005,000 -149,000 791,000             -965,000                                        
        comprehensive income
      28,514,000 33,797,000 42,513,000  38,677,000 47,303,000 57,058,000  66,046,000 71,245,000 59,692,000  74,844,000 62,807,000 66,444,000 111,791,000 33,702,000 17,915,000 9,113,000 -81,903,000 9,644,000 -124,142,000 17,756,000 -23,590,000 38,650,000 18,526,000 36,724,000 139,898,000 29,332,000 38,655,000 24,949,000 87,020,000 25,798,000 49,937,000 15,632,000 97,378,000  46,908,000 -573,413,000    108,749,000 36,543,000 31,243,000 32,504,000 172,143,000 36,167,000 41,116,000 47,960,000 213,405,000 52,015,000 49,951,000 51,319,000                            
        accumulated other comprehensive income
       176,000 590,000     -3,122,000 2,245,000 45,000 -866,000 18,717,000 2,032,000 1,743,000 5,756,000 3,211,000 7,791,000 3,587,000 1,054,000 322,000 170,000                                                             
        class a convertible preferred units
           20,847,000 47,181,000 47,181,000 47,181,000 80,099,000 133,316,000 164,587,000 164,587,000 164,587,000 164,587,000 183,908,000 179,927,000 176,006,000 172,143,000 168,337,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 164,587,000 173,431,000                                                  
        warrant holders’ interest
            4,804,000 23,095,000 32,843,000 47,964,000 47,964,000 47,964,000 47,964,000 47,964,000 47,964,000 47,964,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000 66,816,000                                                  
        total partners' capital
         551,108,000    531,054,000    477,457,000    256,024,000                                                                  
        other incomes
                                                                                       
        loss on extinguishment of debt
                  -2,484,000 -4,048,000          -29,282,000  -29,282,000      -4,107,000  -4,107,000                                                
        total other incomes
              -3,837,000 -3,492,000   -7,625,000 -12,156,000  -38,876,000    -40,968,000 -10,254,000 -10,329,000  -76,735,000 -10,431,000 -41,738,000                                                        
        net income from continuing operations
                     108,902,000    -84,819,000 7,216,000 -125,501,000 18,779,000 -25,414,000 39,163,000 19,106,000 35,765,000 122,360,000 28,565,000 39,123,000 26,088,000 89,208,000 26,499,000 49,817,000 16,971,000 95,214,000 16,419,000 48,633,000                                            
        income from discontinued operations
                             956,000 7,000 245,000 -46,000 17,687,000 -24,000 -34,000 -14,000 -541,000 -433,000 133,000 -207,000 1,678,000 7,112,000 -2,187,000                                            
        income from continuing operations per common unit
                                                                                       
        coal royalty and other
                      47,884,000 33,611,000 32,927,000 120,166,000 25,740,000 31,666,000 31,433,000 191,069,000 39,919,000 64,616,000 49,502,000 178,394,000 42,459,000 48,711,000 45,973,000 158,399,000 49,078,000 36,914,000 34,994,000 144,520,000 27,504,000                                             
        equity in earnings of ciner wyoming
                      6,672,000 2,601,000 1,973,000 10,728,000 1,986,000 -3,058,000 6,272,000 47,089,000 13,818,000 11,333,000 11,682,000 48,306,000 8,836,000 16,529,000 9,621,000 40,457,000 8,993,000 8,389,000 10,294,000 40,061,000 10,753,000 10,188,000 49,918,000                                           
        current assets of discontinued operations
                             1,706,000 988,000 984,000 998,000 993,000 988,000 988,000 991,000 991,000 991,000 991,000 991,000 991,000 991,000 113,218,000                                            
        current liabilities of discontinued operations
                             65,000 174,000 658,000 727,000 947,000   3,000 401,000 458,000 98,000 304,000 353,000 835,000 79,947,000                                            
        non-controlling interest
                            -2,935,000 -2,935,000 -2,935,000 -2,935,000 -2,935,000 -2,935,000 -2,935,000 -2,576,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -3,394,000 -2,150,000 -1,312,000 -650,000 -650,000 -650,000 -650,000 324,000 1,416,000 1,416,000 1,416,000 2,845,000 2,845,000 3,066,000 3,066,000 5,638,000 4,691,000 4,743,000 5,065,000 5,065,000 7,355,000                      
        total capital
                         204,524,000 201,959,000 204,621,000 337,416,000 336,028,000 466,254,000 440,261,000 445,040,000 420,546,000 383,766,000 389,920,000 364,252,000 261,817,000 244,611,000 199,971,000 158,223,000 148,136,000 149,005,000 131,634,000 72,942,000 100,207,000 711,813,000 692,339,000                                        
        total liabilities and capital
                         921,877,000 942,558,000 943,565,000 1,083,422,000 1,085,907,000 1,243,904,000 1,219,443,000 1,272,171,000 1,341,647,000 1,411,934,000 1,411,806,000 1,377,206,000 1,389,164,000 1,495,513,000 1,429,052,000 1,509,250,000 1,444,681,000 1,521,406,000 1,585,086,000 1,684,075,000 1,766,394,000 2,385,105,000 2,393,925,000                                        
        gain on litigation settlement
                                 25,000,000                                                      
        net income attributable to non-controlling interest
                                                                                       
        net income attributable to nrp
                         -84,819,000    -24,458,000 39,170,000 19,351,000  139,537,000 28,900,000 38,220,000       23,531,000 46,446,000  -598,757,000 31,334,000 17,489,000                                        
        comprehensive income attributable to non-controlling interest
                                              -1,244,000                                         
        comprehensive income attributable to nrp
                         -81,903,000    -23,590,000 38,650,000 18,526,000  139,388,000 29,691,000 37,786,000       22,922,000   -599,893,000 31,544,000 16,524,000                                        
        net income attributable to common unitholders and general partner
                          -284,000 -133,114,000 11,279,000 -54,458,000 31,670,000 11,851,000 28,219,000 109,537,000 21,400,000 30,720,000 18,574,000 63,214,000 18,416,000 42,412,000 14,264,000                                               
        prepaid expenses and other
                           4,931,000 1,166,000 1,244,000 3,111,000 5,963,000 4,141,000 3,462,000 4,665,000 4,391,000 3,088,000 5,838,000 7,525,000 3,192,000 4,122,000 6,137,000 3,707,000 4,777,000 4,490,000 2,661,000 2,854,000 4,154,000                                        
        other assets
                           8,554,000 6,774,000 6,989,000 6,274,000 6,806,000 5,677,000 2,491,000 6,188,000 6,184,000 6,489,000 6,547,000 7,741,000 9,172,000 9,270,000 3,791,000 1,898,000 863,000 15,306,000 16,864,000 17,317,000 13,746,000 740,000 560,000 600,000 621,000 497,000 527,000 560,000 604,000 630,000 849,000 886,000 604,000 604,000 579,000 556,000 561,000 616,000 682,000 508,000 569,000 599,000 461,000 497,000 535,000 563,000 825,000 1,032,000 1,207,000 1,095,000 1,257,000 1,420,000 1,726,000 1,968,000 2,310,000 2,552,000 2,699,000 2,944,000 2,882,000 136,000 
        restricted cash
                              12,527,000 14,925,000 17,333,000 104,191,000                                      6,240,000 6,240,000 6,240,000 6,314,000 6,242,000            
        debt modification expense
                                     -7,939,000  -132,000 -7,807,000                                               
        plant and equipment
                              762,000 825,000 893,000 984,000 48,148,000 47,917,000 47,237,000 46,170,000 47,584,000 48,822,000 48,579,000 49,443,000 52,516,000 55,763,000 61,239,000 71,194,000 77,287,000 78,584,000 60,093,000 22,839,000 24,035,000 25,168,000 26,435,000 27,703,000 29,268,000 30,834,000 32,401,000 33,968,000 42,967,000 54,416,000 46,185,000 49,228,000 57,438,000 60,429,000 62,348,000 63,701,000 62,274,000 64,267,000 69,087,000 71,130,000 66,489,000 66,680,000 63,163,000 61,650,000 55,245,000 49,069,000 25,070,000 5,760,000 5,842,000 6,011,000        
        net income (income) attributable to non-controlling interest
                                  359,000                                                     
        comprehensive loss (income) attributable to non-controlling interest
                                  359,000                                                     
        long-term contracts receivable
                               37,973,000 38,464,000 38,945,000 39,416,000 39,878,000 40,331,000 40,776,000 41,211,000 41,638,000                                                
        gain on asset sales
                               246,000 256,000 2,441,000 163,000 210,000 660,000 3,856,000 171,000 3,361,000 44,000 29,081,000 6,426,000 -1,071,000                                            
        accounts receivable—affiliates
                                 34,000 22,000 140,000 94,000 161,000 243,000 292,000 7,605,000 6,658,000 7,057,000 8,616,000 6,864,000 7,450,000                                          
        long-term assets of discontinued operations
                                                                                       
        other assets—affiliate
                                     156,000 892,000 1,265,000 952,000 1,018,000 1,034,000 1,046,000 1,124,000 1,525,000                                          
        accounts payable—affiliates
                                 1,866,000 608,000 1,453,000 2,093,000 562,000 670,000 942,000 1,196,000 940,000 829,000 779,000 1,464,000 2,566,000 939,000 936,000                                        
        accrued liabilities—affiliates
                                     515,000                                                  
        long-term liabilities of discontinued operations
                                                                                       
        other non-current liabilities—affiliate
                                     346,000                                                  
        coal royalty and other—affiliates
                                 484,000 59,000 188,000 237,000 23,402,000 335,000 12,712,000 16,144,000 65,595,000 21,434,000                                             
        transportation and processing services—affiliate
                                                                                       
        operating and maintenance expenses—affiliates
                                 11,615,000 2,414,000 4,065,000 2,465,000 9,534,000 2,154,000 2,219,000 2,555,000 10,925,000 4,062,000 2,402,000 16,031,000                                           
        amortization expense—affiliate
                                     1,008,000  240,000 768,000 3,185,000 902,000 704,000                                            
        general and administrative
                                 12,838,000 2,249,000 2,414,000 3,405,000 13,513,000 2,648,000 2,031,000 6,078,000 16,979,000 4,268,000 3,173,000 7,036,000 5,140,000 2,234,000 7,454,000 36,437,000 7,664,000 9,029,000 5,857,000 36,821,000 7,305,000 8,878,000 11,586,000 29,714,000 8,225,000 7,029,000 8,950,000 29,553,000 5,521,000 6,439,000 10,196,000 29,893,000 8,761,000 6,548,000 23,102,000 4,586,000 5,834,000 7,506,000 6,890,000 4,149,000 3,687,000 5,559,000 6,634,000 3,475,000 3,420,000 4,115,000 3,527,000 3,162,000 3,312,000 11,503,000 2,523,000 2,422,000 2,711,000 8,923,000 
        general and administrative—affiliates
                                 3,658,000 934,000 849,000 931,000 4,989,000 1,207,000 852,000 1,124,000 3,591,000 867,000 866,000 5,312,000 4,144,000 3,535,000 3,786,000                                        
        other income
                                   -17,734,000 -17,970,000 -94,767,000 -20,032,000 -587,000 -20,071,000 -90,531,000 -22,488,000 -22,108,000 -93,809,000 -23,711,000 -23,342,000 -22,928,000                                        
        interest expense—affiliate
                                         -523,000  -61,000                                            
        total other income
                                 -70,178,000 -17,501,000                                                     
        less: net income attributable to non-controlling interest
                                 -510,000  -869,000          1,244,000 -1,244,000                                         
        less: comprehensive income attributable to non-controlling interest
                                 -510,000  -869,000                                                    
        inventory
                                  9,572,000 8,048,000 8,071,000 7,553,000 7,671,000 7,841,000 7,624,000 6,893,000 7,160,000 7,832,000 7,835,000 6,849,000 7,126,000 5,790,000 5,814,000                                       
        construction aggregates
                                  30,398,000 34,233,000 26,424,000 112,970,000 34,710,000 33,555,000                                                
        road construction and asphalt paving services
                                  6,250,000 6,176,000 728,000                                                   
        add: comprehensive income from unconsolidated investment and other
                                   -434,000 -1,125,000 -1,647,000 -268,000 -13,000 -1,132,000 486,000 -609,000 462,000 -1,693,000 -1,136,000                                          
        interest income
                                    36,000 181,000 48,000 69,000 17,000 39,000 3,000 7,000 18,000  1,000 15,000 96,000 8,000 41,000 26,000 238,000 18,000 173,000 41,000 162,000 35,000 24,000 45,000 69,000 16,000 16,000 8,000 35,000 13,000 8,000 213,000 18,000 96,000 82,000 312,000 444,000 736,000 686,000 817,000 665,000 755,000 518,000 392,000 331,000 231,000 349,000 78,000 60,000 52,000 206,000 
        current assets:
                                                                                       
        intangible assets, net—affiliate
                                        49,043,000 49,811,000 50,668,000 51,570,000                                            
        long-term contracts receivable—affiliate
                                        42,619,000 43,785,000 44,224,000 44,572,000 47,359,000 48,520,000 49,236,000 49,610,000  50,411,000                                      
        current liabilities:
                                                                                       
        deferred revenue—affiliates
                                        68,735,000 71,632,000 74,663,000 78,793,000 82,853,000 83,654,000 87,116,000 86,315,000                                        
        partners’ capital:
                                                                                       
        revenues and other income:
                                                                                       
        transportation and processing
                                     14,510,000                                                  
        transportation and processing—affiliates
                                     6,012,000                                                  
        road construction and asphalt paving
                                     18,411,000                                                  
        operating expenses:
                                                                                       
        convertible preferred units
                                      169,606,000 160,377,000 159,292,000                                               
        warrant holders interest
                                      66,816,000                                                 
        warrant liabilities
                                       37,457,000 61,417,000                                               
        warrant issuance expense
                                        -5,709,000                                               
        fair value adjustments for warrant liabilities
                                       23,960,000 16,569,000                                               
        current assets held for sale
                                        17,500,000  5,520,000                                             
        vantacore
                                        27,221,000 120,802,000 31,757,000 31,642,000 139,013,000                                           
        non-current assets of discontinued operations
                                                                                       
        long-term debt, net—affiliate
                                            19,930,000 19,923,000 19,917,000 19,911,000                                        
        non-current liabilities of discontinued operations
                                                                                       
        net income attributable to limited partners:
                                                                                       
        continuing operations
                                         93,585,000 16,155,000 47,726,000                                            
        discontinued operations
                                         1,644,000 6,970,000 -2,143,000                                            
        total
                                         95,229,000 23,125,000 45,583,000                                            
        net income attributable to the general partner:
                                                                                       
        basic and diluted net income per common unit:
                                                                                       
        average number of common units outstanding
                                         12,232,000                                              
        weighted-average number of common units outstanding
                                          12,232,000 12,232,000 12,230,000 122,300,000 122,300,000 122,300,000 113,262,000    109,584,000    106,028,000                               
        less: comprehensive loss attributable to non-controlling interest
                                             1,244,000                                          
        coal and hard mineral royalty and other
                                           58,892,000                                            
        coal and hard mineral royalty and other—affiliates
                                           17,504,000                                            
        oil and gas royalty
                                           1,091,000                                            
        goodwill
                                             4,840,000 4,840,000 29,465,000 52,012,000                                       
        coal, hard mineral royalty and other
                                            156,638,000                                           
        coal, hard mineral royalty and other—affiliates
                                            89,715,000                                           
        oil and gas
                                            53,565,000                                           
        net income attributable to partners:
                                                                                       
        limited partners
                                            -559,492,000 -586,013,000 30,707,000 17,139,000 106,653,000 35,450,000 30,779,000 31,953,000 168,636,000 35,403,000 40,244,000 46,948,000 209,088,000 50,961,000 48,939,000 50,283,000 52,945,000 -28,700,000 51,305,000 44,376,000 125,925,000 39,350,000 16,864,000 78,954,000 25,161,000 4,804,000 21,598,000 30,562,000 25,853,000 22,902,000 18,145,000 17,779,000 21,483,000 21,848,000 25,608,000 19,999,000 23,464,000 19,390,000 57,008,000 18,646,000 14,685,000 10,915,000  
        general partner
                                            -12,228,000 -12,744,000 627,000 350,000 2,177,000 723,000 628,000 652,000 3,442,000 723,000 821,000 958,000 4,267,000 1,040,000 999,000 1,026,000 1,081,000 -586,000 1,047,000 906,000 2,570,000 803,000 344,000 1,611,000 513,000 98,000 441,000 6,647,000 5,215,000 4,119,000 3,074,000 2,819,000 2,641,000 2,253,000 2,095,000 1,103,000 1,155,000 830,000 1,705,000 605,000 394,000 247,000  
        basic and diluted net income per common unit
                                            -45,750 -4,790 250 140                                        
        coal related revenues
                                             35,469,000 28,562,000 30,421,000 226,724,000 65,193,000 55,361,000 52,373,000                                    
        coal related revenues—affiliates
                                             19,535,000 32,342,000 19,061,000                                        
        aggregates related revenues
                                             42,326,000 42,886,000 28,946,000 54,124,000                                       
        oil and gas related revenues
                                             12,416,000 14,839,000 15,230,000 59,566,000 9,601,000 17,822,000 10,058,000                                    
        equity in earnings of unconsolidated investment
                                             12,617,000 11,599,000 12,523,000                                        
        property taxes
                                             2,528,000 3,070,000 3,004,000 13,609,000 3,520,000 3,378,000 3,967,000 15,416,000 4,009,000 3,849,000 3,947,000 15,273,000 3,602,000 3,331,000 4,488,000 12,640,000 2,974,000 3,577,000 3,012,000 11,270,000 3,552,000 2,651,000 11,636,000 3,311,000 2,514,000 3,211,000 3,105,000 2,392,000 2,963,000 2,645,000 2,228,000 1,532,000 1,546,000 1,749,000 1,552,000 1,547,000 1,434,000 5,349,000 1,377,000 1,278,000 1,306,000 5,069,000 
        other
                                             588,000 4,332,000 492,000 4,279,000 899,000 1,291,000 1,585,000 1,691,000 281,000 4,097,000 802,000 1,042,000 218,000 526,000 632,000 832,000 391,000 438,000 743,000 910,000 197,000 771,000 930,000 254,000 704,000 668,000 491,000 786,000 237,000 514,000 791,000 307,000 590,000 565,000 36,000 285,000 536,000 786,000 38,000 465,000 819,000 1,186,000 
        costs and expenses:
                                                                                       
        coal related expenses
                                             649,000 504,000 1,321,000                                        
        coal related expenses—affiliates
                                             -68,000 109,000                                         
        aggregates related expenses
                                             31,107,000 32,800,000 22,407,000                                        
        oil and gas related expenses
                                             3,049,000 2,999,000 3,762,000                                        
        property, franchise and other taxes
                                             4,286,000 5,066,000 5,138,000 21,279,000 4,767,000 6,201,000 4,868,000 16,463,000 4,234,000 4,225,000 4,351,000 17,678,000 4,853,000 3,771,000 5,016,000 14,486,000 3,915,000 3,306,000 3,697,000 15,107,000 4,580,000 3,734,000 14,996,000 4,273,000 3,151,000 3,975,000 4,098,000 3,649,000 3,993,000 3,524,000 3,101,000 2,142,000 2,099,000 2,245,000 1,954,000 1,954,000       
        accounts receivable—affiliate
                                              8,192,000 5,851,000                                        
        comprehensive (income) income from unconsolidated investment and other
                                              210,000                                         
        accounts receivable — affiliates
                                                9,494,000    7,666,000    10,613,000    10,138,000 12,342,000 4,713,000 6,599,000 7,915,000 7,850,000  4,342,000                    
        equity and other unconsolidated investments
                                                264,020,000 262,414,000 262,661,000 267,359,000 269,338,000 242,407,000 279,877,000 298,620,000                                
        loan financing costs
                                                13,905,000 9,841,000 10,357,000 10,916,000 11,502,000 11,936,000 5,383,000 5,648,000 4,291,000 4,430,000 4,569,000 4,707,000 4,846,000 4,782,000 3,272,000 2,322,000 2,436,000 2,550,000 2,777,000 2,891,000 3,005,000 3,120,000 3,235,000 2,889,000 2,993,000 3,202,000 3,300,000 3,223,000 2,182,000 2,266,000 2,344,000 2,217,000 1,737,000 1,778,000 1,837,000 2,048,000 2,327,000 2,604,000 2,884,000 
        long-term contracts receivable — affiliates
                                                50,008,000    51,732,000    55,576,000                               
        liabilities and partners’ capital
                                                                                       
        accounts payable and accrued liabilities
                                                32,416,000 13,907,000 11,765,000 11,361,000 8,659,000 6,032,000 3,399,000 3,345,000 3,693,000 3,223,000 2,905,000 2,685,000 2,366,000 2,100,000 1,402,000 740,000 1,388,000 2,486,000 681,000 914,000 927,000 804,000 568,000 2,995,000 2,316,000 2,550,000 2,736,000 3,837,000            
        accounts payable — affiliates
                                                950,000    391,000    957,000    375,000    499,000 178,000 179,000 179,000  175,000 20,263,000                 
        accrued incentive plan expenses — current portion
                                                7,048,000        7,718,000    8,374,000 7,690,000 6,444,000 5,885,000 6,788,000 5,734,000 3,851,000 4,627,000  3,982,000 3,184,000 5,235,000   4,127,000   4,763,000 4,262,000 1,941,000 1,685,000  1,559,000   831,000 1,186,000 
        property, franchise and other taxes payable
                                                8,318,000 5,764,000 6,981,000 5,293,000 7,830,000 5,126,000 6,593,000 5,552,000 7,952,000 5,602,000 5,734,000 3,824,000 6,316,000 4,499,000 5,513,000 4,088,000 6,926,000 5,603,000 5,112,000 6,164,000 4,490,000 4,543,000 3,984,000 5,425,000 3,953,000 4,634,000 4,589,000 4,727,000 3,991,000 3,833,000 4,541,000 3,078,000 2,690,000       
        accrued incentive plan expenses
                                                6,554,000 6,887,000 6,071,000 5,473,000 10,526,000 8,981,000 8,308,000 7,091,000 8,865,000 8,915,000 7,801,000 6,883,000 11,670,000 10,431,000 10,561,000 9,423,000 11,347,000 8,689,000 5,626,000 7,371,000 5,594,000 5,007,000 3,771,000 6,305,000 3,772,000 5,599,000 5,237,000 3,578,000 3,680,000 3,247,000 2,609,000 5,502,000 4,369,000 3,415,000 3,271,000 2,245,000 1,619,000 1,254,000 1,070,000 
        asset retirement obligation
                                                4,905,000                         39,000 39,000 39,000            
        common units outstanding:
                                                709,019,000 613,176,000 609,001,000 605,711,000 606,774,000    605,019,000    629,253,000   793,620,000 806,529,000 822,365,000 726,797,000 747,437,000 757,550,000 769,892,000                  
        total liabilities and partners’ capital
                                                2,444,724,000 1,938,544,000 1,938,808,000 1,946,643,000 1,991,856,000 1,950,635,000 1,975,851,000 1,985,371,000 1,764,672,000 1,713,678,000 1,694,360,000 1,671,874,000 1,665,649,000 1,676,264 1,792,700,000 1,718,295,000 1,664,036,000 1,603,002,000 1,544,833,000 1,523,590,000 1,510,123,000 1,508,085,000 1,459,228,000 1,305,937,000 1,307,104,000 1,297,335,000 1,298,685,000 1,288,096,000 781,368,000 723,846,000 729,713,000 661,196,000 618,273,000 622,690,000  600,856,000 593,957,000 607,297,000  
        equity and other unconsolidated investment income
                                                41,416,000 9,685,000 9,401,000 9,779,000 34,186,000 7,238,000 7,882,000 7,048,000                                
        oil and gas lease operating expenses
                                                9,144,000 2,147,000   739,000                                   
        aggregates operating expenses
                                                32,309,000                                       
        transportation costs
                                                1,604,000 354,000 462,000 422,000 1,644,000 455,000 328,000 459,000 1,944,000 446,000 527,000 473,000 2,033,000 540,000 523,000 468,000 1,864,000 614,000 265,000 1,611,000 403,000 473,000 268,000 408,000 121,000 79,000 27,000 43,000            
        coal royalty and override payments
                                                3,975,000    1,103,000 284,000 187,000 355,000 1,857,000 523,000 673,000 200,000 1,022,000 233,000 159,000 308,000 1,498,000 258,000 692,000 2,388,000 353,000 372,000 489,000 343,000 309,000 246,000 382,000 286,000 296,000 263,000 691,000 1,071,000 745,000 553,000  450,000    
        income before non-controlling interest
                                                108,830,000 36,173,000 31,407,000 32,605,000 172,078,000 36,126,000 41,065,000 47,906,000 213,355,000 52,001,000 49,938,000 51,309,000 55,024,000 -29,286,000 52,403,000 45,282,000 154,461,000 40,153,000                      
        net income attributable to:
                                                                                       
        basic and diluted net income per limited partner unit
                                                940 320 280 290 1,540 320 370 430 1,970 480   500 -270 480 420 1,540 510 240 1,170 360 70 330 470 400               
        accounts receivable – affiliates
                                                 10,547,000 9,018,000 10,764,000  8,550,000 13,597,000 12,978,000   12,897,000 13,040,000                            
        accounts payable – affiliates
                                                 485,000 445,000 869,000  727,000 1,472,000 432,000   398,000 1,139,000         156,000                   
        accrued incentive plan expenses – current portion
                                                 6,535,000 6,880,000 5,329,000 8,341,000 7,522,000 7,056,000 6,237,000   6,982,000 6,569,000         4,235,000    3,542,000 4,260,000  3,224,000 5,326,000     1,420,000   1,122,000   
        aggregate related revenues
                                                 2,655,000 3,563,000 3,396,000                                    
        royalty payments
                                                 3,029,000 201,000 155,000                                    
        weighted-average number of units outstanding
                                                 111,244,000 110,403,000 109,848,000  109,812,000 109,812,000 108,887,000  106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 106,028,000 81,917,000 77,896,000 69,451,000 67,702,000 69,451,000 66,946,000 64,891,000 64,891,000 64,891,000               
        long-term contracts receivable – affiliates
                                                  50,787,000                                     
        oil and gas lease operating expense
                                                  2,291,000 1,921,000                                    
        long-term contracts receivable - affiliates
                                                   51,135,000                                    
        revenues:
                                                                                       
        coal royalties
                                                    212,663,000 52,305,000 58,210,000 54,442,000 260,734,000 70,259,000 62,878,000 59,916,000 279,221,000 76,430,000 69,788,000 65,365,000 221,761,000 60,142,000 47,161,000 196,621,000 49,307,000 46,380,000 52,607,000 60,026,000 49,152,000 44,378,000 40,733,000 40,973,000 36,902,000 36,527,000 39,110,000 34,267,000 37,957,000 32,530,000 106,456,000 30,315,000 26,179,000 22,848,000 73,770,000 
        aggregate royalties
                                                    7,643,000 2,566,000 1,751,000 1,552,000 6,598,000 1,643,000 1,702,000 1,716,000 6,734,000 2,099,000 1,831,000 1,194,000 4,230,000 1,606,000 891,000 5,580,000 1,700,000 1,347,000 1,650,000 1,933,000 3,362,000 2,096,000 1,944,000 1,745,000            
        processing fees
                                                    5,049,000 1,377,000 1,329,000 1,180,000 8,299,000 1,641,000 3,138,000 2,126,000 13,475,000                           
        transportation fees
                                                    17,977,000 4,742,000 3,832,000 4,925,000 19,513,000 5,007,000 5,246,000 4,108,000 16,688,000 4,765,000 3,745,000 4,098,000 14,564,000 4,285,000 2,775,000 12,517,000 3,049,000 3,489,000 2,096,000 3,361,000 1,649,000 1,000,000 845,000 461,000            
        oil and gas revenues
                                                    17,080,000                                   
        minimums recognized as revenue
                                                    8,285,000 998,000 836,000 4,591,000 23,956,000 1,096,000 938,000 11,714,000 9,148,000 1,582,000 1,841,000 507,000 14,199,000 3,782,000 3,374,000 1,266,000 775,000 67,000 223,000 149,000 307,000 913,000 331,000 454,000 633,000 250,000 371,000 431,000 481,000 453,000 1,763,000 352,000 165,000 763,000 2,033,000 
        override royalties
                                                    13,499,000 2,927,000 3,179,000 4,905,000 15,527,000 3,359,000 3,497,000 5,142,000 14,523,000 4,131,000 3,492,000 3,043,000 11,258,000 2,625,000 2,967,000 9,251,000 2,077,000 1,336,000 2,548,000 2,006,000 2,499,000 953,000 1,023,000 1,018,000 283,000 181,000 303,000 487,000 209,000 615,000 3,222,000 956,000 757,000 677,000 1,022,000 
        long-term contracts receivable – affiliate
                                                     53,603,000 54,080,000    55,371,000                             
        common units outstanding
                                                     621,363,000 646,356,000 666,523,000  604,430,000 611,845,000 621,220,000  701,602,000 787,560,000                         
        oil and gas royalties
                                                     3,886,000 4,093,000 1,763,000 9,160,000 1,246,000 4,078,000 1,388,000 14,017,000 5,059,000 1,996,000 2,992,000 7,720,000 1,013,000 1,099,000 7,520,000 1,203,000 953,000 1,493,000 1,933,000 1,445,000 1,388,000 1,278,000 1,258,000 853,000 928,000 1,719,000         
        lease operating expense
                                                     483,000                                  
        total revenues
                                                      86,804,000 94,332,000 379,147,000 94,175,000 90,664,000 91,872,000 377,683,000 103,771,000 91,409,000 84,852,000 301,401,000 80,752,000 63,519,000 256,084,000 63,962,000 59,487,000 66,733,000 75,592,000 64,055,000 56,366,000 51,097,000 50,207,000 41,491,000 40,982,000 46,528,000 38,735,000 41,697,000 36,247,000  34,221,000 29,497,000 26,362,000  
        long-term contracts receivable - affiliate
                                                       55,021,000  55,741,000                              
        obligation related to acquisition
                                                            500,000      4,477,000 2,969,000 11,843,000                   
        holders of incentive distribution rights
                                                                  12,983,000 4,977,000 4,977,000 12,180,000 11,381,000 142,000  -48,000 392,000 1,110,000 1,549,000 1,296,000 995,000 436,000 345,000 196,000 105,000 110,000 44,000 12,000  
        accounts receivable - affiliates
                                                         10,077,000                              
        coal and other mineral rights
                                                         1,352,800,000 1,324,654,000 1,310,590,000 1,257,501,000 1,289,874,000 1,367,532,000 1,362,768,000 1,281,636,000 1,241,714,000 1,193,908,000 1,151,313,000 1,157,092,000 1,133,023,000 1,094,197,000 1,001,995,000 1,016,655,000 1,004,081,000 1,015,616,000 1,012,948,000 655,078,000 626,858,000 617,487,000 569,534,000 530,961,000 539,380,000 523,844,000 531,592,000 538,743,000 544,530,000  
        accounts payable - affiliates
                                                         573,000                              
        obligation related to acquisitions
                                                           500,000  500,000 4,100,000 6,025,000                        
        accrued incentive plan expenses - current portion
                                                         7,585,000                          1,356,000    
        operating costs and expenses:
                                                                                       
        asset impairment
                                                             90,932,000                          
        total operating costs and expenses
                                                         28,532,000 27,172,000 27,048,000 273,548,000 120,294,000 26,593,000 28,991,000 105,340,000 30,408,000 22,607,000 102,109,000 22,567,000 31,826,000 25,316,000 28,487,000 23,287,000 21,050,000 22,019,000 21,816,000 12,922,000 13,018,000 14,904,000 14,773,000 14,486,000 13,574,000  12,514,000 12,025,000 12,104,000  
        other income:
                                                                                       
        less non-controlling interest
                                                              -51,000                         
        long-term contracts – affiliate
                                                           47,663,000                            
        coal processing fees
                                                             3,967,000 3,173,000 3,089,000 9,604,000 2,343,000 1,644,000 7,673,000 1,508,000 2,400,000 1,900,000 1,757,000 1,897,000 1,374,000 1,112,000 918,000            
        accounts receivable — affiliate
                                                                  5,334,000   3,906,000 2,071,000 4,768,000   570,000   8,000  6,000 6,000  25,000    1,437,000 
        accounts receivable – affiliate
                                                                    2,211,000    1,582,000 1,009,000  337,000 59,000           
        common units
                                                                      706,222,000 723,935,000 725,494,000 661,094,000 667,095,000 641,357,000 298,571,000 298,190,000 297,062,000 249,536,000 248,503,000 245,213,000 243,814,000 245,764,000  243,896,000 143,956,000 
        accounts payable — affiliate
                                                                       105,000   105,000   86,000 87,000 78,000 78,000  105,000   123,000 305,000 
        asset retirement obligations
                                                                       39,000 39,000               
        other holders of incentive distribution rights
                                                                       3,144,000 2,784,000 1,907,000 1,412,000 1,283,000 1,150,000 943,000 821,000 363,000 353,000 227,000 281,000 117,000 49,000   
        accounts payable – affiliate
                                                                        104,000 368,000  691,000 183,000     92,000   111,000   
        general partners’ interest
                                                                        13,417,000 15,418,000 16,412,000 17,873,000 12,058,000 11,559,000 10,944,000   9,030,000 8,802,000 8,867,000 8,670,000 8,606,000 6,474,000 
        subordinated units
                                                                         78,701,000 79,973,000 81,965,000 126,351,000 126,029,000 125,328,000 162,191,000 161,280,000 158,527,000 157,324,000 158,759,000 157,217,000 157,137,000 158,633,000 
        basic and diluted net income per limited partner unit:
                                                                                       
        common
                                                                         350 280 280 850 860 1,010 790 920 770 2,290 740 580 470 1,590 
        subordinated
                                                                         350 280 280 850 860 1,010 790 920 770 2,290 740 580 470 1,590 
        weighted-average number of units outstanding:
                                                                                       
        class b
                                                                          280 280            
        class b units
                                                                           27,825,000            
        depletion and amortization
                                                                               8,221,000 8,625,000 7,879,000 30,957,000 8,077,000 7,493,000 7,348,000 25,365,000 
        property and franchise taxes payable
                                                                                 3,461,000 3,460,000 2,950,000 2,814,000 3,109,000 2,799,000 
        taxes other than income
                                                                                 1,830,000 6,835,000 1,464,000 1,712,000 1,657,000 5,810,000 
        coal royalty payments
                                                                                  2,045,000  398,000 388,000 913,000 
        loss on early extinguishment of debt
                                                                                  -1,135,000     
        income from sale of oil and gas properties
                                                                                      -55,000 
        income from interest rate hedge
                                                                                      -499,000 
        accounts receivable - affiliate
                                                                                       
        accounts payable - affiliate
                                                                                   111,000    
        common units (outstanding: 13,986,906 in 2004, 11,353,658 in 2003).
                                                                                    243,864,000   
        override payments
                                                                                      386,000 
        coal and other mineral rights owned
                                                                                      447,334,000 
        coal and other mineral rights leased
                                                                                      31,294,000 
        other income interest expense
                                                                                      -6,814,000 
        general partners’ net income
                                                                                      738,000 
        limited partners’ net income
                                                                                      36,169,000 
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2025-12-31 2025-09-30 2025-06-30 2025-03-31 2024-12-31 2024-09-30 2024-06-30 2024-03-31 2023-12-31 2023-09-30 2023-06-30 2023-03-31 2022-12-31 2022-09-30 2022-06-30 2022-03-31 2021-12-31 2021-09-30 2021-06-30 2021-03-31 2020-12-31 2020-09-30 2020-06-30 2020-03-31 2019-12-31 2019-09-30 2019-06-30 2019-03-31 2018-12-31 2018-09-30 2018-06-30 2018-03-31 2017-12-31 2017-09-30 2017-06-30 2017-03-31 2016-12-31 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-12-31 2014-09-30 2014-06-30 2014-03-31 2013-12-31 2013-09-30 2013-06-30 2013-03-31 2012-12-31 2012-09-30 2012-06-30 2012-03-31 2011-12-31 2011-09-30 2011-06-30 2011-03-31 2010-12-31 2010-09-30 2010-06-30 2010-03-31 2009-12-31 2009-09-30 2009-06-30 2009-03-31 2008-12-31 2008-09-30 2008-06-30 2008-03-31 2007-12-31 2007-09-30 2007-06-30 2007-03-31 2006-12-31 2006-09-30 2006-06-30 2006-03-31 2005-12-31 2005-09-30 2005-06-30 2005-03-31 2004-10-17 2004-09-30 
                                                                                              
          cash flows from operating activities
                                                                                              
          net income
        30,998,000 30,905,000 34,211,000 40,253,000 42,772,000 38,595,000 46,064,000 56,213,000 64,980,000 63,846,000 70,334,000 79,275,000 63,218,000 74,555,000 66,820,000 63,899,000 55,641,000 29,498,000 15,382,000 8,381,000 14,687,000 7,216,000 -125,501,000 18,779,000 -118,698,000 39,170,000 19,351,000 35,719,000 49,058,000 25,826,000 39,089,000 26,074,000 30,707,000 -8,754,000 49,950,000 16,764,000 3,488,000 23,531,000 46,446,000 23,427,000 -21,786,000 -600,001,000 32,578,000 17,489,000 8,645,000 36,173,000 31,407,000 32,605,000 46,981,000 36,126,000 41,065,000 47,906,000 60,107,000 52,001,000 49,938,000 51,309,000 -14,322,000 -29,286,000 52,352,000 45,282,000 42,506,000 40,154,000 41,610,000 30,191,000 32,927,000 30,651,000 17,082,000 33,420,000 48,463,000 47,338,000 40,353,000 33,852,000 29,059,000 28,928,000 22,631,000 21,881,000 23,248,000 25,274,000 25,044,000 28,524,000 24,955,000 21,465,000 24,972,000 20,447,000 13,324,000 19,368,000 
          adjustments to reconcile net income to net cash from operating activities:
                                                                                              
          depreciation, depletion and amortization
        3,344,000 3,868,000 3,754,000 3,989,000 2,827,000 4,730,000 3,324,000 4,654,000 6,020,000 4,594,000 3,792,000 4,083,000 5,954,000 6,850,000 5,847,000 3,868,000 3,930,000 5,182,000 4,871,000 5,092,000 3,013,000 2,111,000 2,062,000 2,012,000 3,186,000 3,384,000 3,970,000 4,392,000 -3,052,000 8,221,000 8,563,000 7,957,000 8,790,000 8,306,000 8,165,000 9,724,000 10,906,000 11,929,000 6,231,000 14,021,000 18,152,000 26,624,000 30,660,000 25,392,000 30,258,000 18,621,000 16,350,000 14,647,000 14,352,000 17,852,000 17,411,000 14,762,000 16,155,000 14,485,000 15,172,000 12,409,000 15,477,000 19,153,000 16,166,000 14,322,000 12,930,000 16,195,000 16,485,000 11,368,000 11,986,000 12,952,000 21,996,000 13,078,000 15,405,000 17,042,000 16,748,000 15,059,000 14,067,000 13,045,000 12,527,000 11,752,000 7,597,000 7,009,000 7,236,000 7,853,000       
          distributions from unconsolidated investment
        4,900,000 2,940,000 10,667,000 6,320,000 7,584,000 14,210,000 15,338,000 23,010,000 32,350,000 10,780,000 10,780,000 10,339,000 10,486,000 13,230,000 7,350,000 3,920,000 7,105,000 7,105,000 6,370,000 6,370,000 9,310,000 9,800,000 9,800,000 12,250,000 12,250,000 10,153,000                                                       
          equity in earnings from unconsolidated investment
                                                                                              
          gain on asset sales and disposals
        -906,000 -729,000 -247,000 -36,000 -1,000 -4,643,000 -165,000 -2,001,000 -854,000 -5,000 -96,000 -383,000 -354,000   -2,000 -68,000 -116,000 -59,000 -116,000   111,000                                                              
          asset impairments
        20,000    424,000 63,000   3,583,000 812,000 43,000 19,000 986,000 57,000 16,000 4,043,000 2,668,000 934,000   147,730,000    18,038,000 242,000 1,253,000 1,778,000 9,245,000                                                  
          bad debt expense
        -111,000 1,731,000 -1,320,000 451,000 3,647,000 1,058,000 293,000 -813,000 1,431,000 1,621,000 -198,000 -610,000 421,000 1,000 -388,000 1,028,000 857,000 2,069,000 -737,000 383,000 86,000 258,000 3,847,000 -190,000                                                               
          unit-based compensation expense
        3,015,000 2,724,000 2,662,000 2,717,000 2,431,000 3,002,000 2,912,000 2,964,000 3,007,000 2,766,000 2,646,000 2,491,000 1,557,000 1,429,000 1,339,000 1,448,000 1,202,000 1,118,000 593,000 1,126,000 1,004,000 913,000 924,000 729,000 519,000 466,000 475,000 901,000 208,000 153,000 281,000 792,000                                                       
          amortization of debt issuance costs and other
        -3,261,000 368,000 -281,000 -168,000 1,094,000 -1,655,000 -199,000 -749,000 260,000 477,000 541,000 25,000 523,000 215,000 1,297,000 375,000 366,000 653,000 977,000 269,000 832,000 1,577,000 -1,534,000 448,000 464,000 1,072,000 355,000 1,796,000 4,793,000 568,000 1,202,000 771,000 2,546,000                                                      
          change in operating assets and liabilities:
                                                                                              
          accounts receivable
        1,966,000 -3,115,000 3,610,000 -149,000 1,574,000 -6,640,000 2,918,000 9,433,000 -4,254,000 -2,610,000 -361,000 7,061,000 -8,553,000 2,494,000 -5,033,000 -7,579,000 -2,083,000 -9,163,000 162,000 -3,331,000 4,859,000 4,621,000 8,446,000 -5,073,000 -10,766,000 1,147,000 8,511,000 -4,927,000 753,000 1,922,000 -3,737,000 -5,189,000 698,000 5,210,000 -2,336,000 -1,267,000 772,000 -4,263,000 -1,860,000 5,782,000 4,567,000 -641,000 -2,550,000 15,110,000 -3,151,000 -3,857,000 3,375,000 -7,060,000 -2,651,000 5,227,000 4,781,000 -531,000 -1,468,000 -5,185,000 7,088,000 -1,237,000 5,819,000 -10,439,000 2,199,000 -4,530,000 2,714,000 -256,000 -2,966,000 -2,119,000 601,000 -1,885,000 5,328,000 -3,463,000 6,708,000 -2,323,000 -5,252,000 -3,719,000 2,364,000 -4,835,000 1,273,000 -4,072,000 1,013,000 -2,332,000 -103,000 -4,000 -3,847,000 347,000 -979,000 -2,390,000  -274,000 
          accounts payable
        272,000 -43,000 -526,000 546,000 -73,000 49,000 -580,000 629,000 -258,000 -381,000 72,000 -541,000 -186,000 210,000 73,000 -60,000 481,000 182,000 -83,000 -10,000 14,000 144,000 -44,000 93,000 -412,000 355,000 -561,000 -616,000 -908,000 495,000 1,020,000 -845,000 631,000 684,000 -940,000 986,000 72,000 485,000 198,000 -48,000 -1,006,000 -3,350,000 3,223,000 -2,642,000                                  255,000 -57,000 37,000  202,000 161,000 -285,000   
          accrued liabilities
        1,719,000 358,000 2,296,000 -7,990,000 3,829,000 392,000 1,916,000 -8,225,000 6,063,000 498,000 2,019,000 -8,805,000 5,766,000 278,000 2,047,000 -7,156,000 3,859,000 357,000 1,838,000 -3,034,000 780,000 791,000 -915,000 -2,861,000 1,427,000 439,000 642,000 -6,164,000 2,118,000 1,397,000 1,788,000 -5,169,000 4,009,000 -8,554,000 4,182,000 -8,080,000 -2,669,000 10,418,000 2,769,000 -5,900,000 -7,735,000 8,478,000 -6,340,000 921,000                                           
          accrued interest
        -423,000 324,000 -388,000 254,000 -473,000 457,000 -677,000 412,000 -641,000 599,000 -627,000 263,000 -3,238,000 3,177,000 -7,413,000 7,250,000 -7,472,000 7,262,000 -7,424,000 7,133,000 -7,559,000 7,248,000 -7,351,000 7,060,000 -12,048,000 7,163,000 2,889,000 -10,033,000 8,806,000 -9,069,000 8,902,000 -9,777,000             -2,160,000 4,964,000 -6,145,000 4,373,000 9,517,000 -2,022,000 1,349,000 -1,925,000 2,275,000 -2,613,000 2,737,000 -2,895,000 2,660,000 -3,578,000 8,902,000 -7,034,000 6,969,000 -7,136,000 6,814,000 -7,136,000 7,064,000 -7,123,000 7,054,000 -3,145,000 3,342,000 -2,934,000 2,655,000 -2,920,000 2,596,000 -2,763,000 3,031,000 -434,000 75,000 1,020,000 -689,000 1,906,000 -1,286,000 2,385,000 -2,078,000 2,247,000  2,180,000 
          deferred revenue
        7,211,000 1,577,000 -986,000 -3,227,000 419,000 14,854,000 899,000 1,028,000 1,480,000 -2,163,000 -2,646,000 -154,000 1,670,000 -7,519,000 -2,259,000 -7,316,000 2,428,000 -2,652,000 677,000 -146,000 -461,000 -273,000 2,202,000 8,265,000 3,188,000 -1,236,000 -7,218,000 4,534,000 10,265,000 3,163,000 3,691,000 2,346,000 -5,786,000 -4,494,000 3,412,000 1,077,000 4,881,000 -2,558,000 -34,141,000 -4,063,000 1,570,000 -1,464,000 1,654,000 5,845,000 6,329,000 4,246,000 3,357,000 3,742,000 5,909,000 3,380,000 5,445,000 4,506,000 -183,000 5,316,000 9,000,000 -2,449,000 5,210,000 12,869,000 7,764,000 5,434,000 13,237,000 8,613,000 7,628,000 13,013,000 15,958,000 1,996,000 2,798,000 5,512,000 479,000 1,263,000 313,000 2,413,000 4,825,000 2,890,000 4,016,000 3,901,000 4,770,000 625,000 1,040,000 -632,000 1,020,000 315,000 -176,000 -2,155,000  -118,000 
          other items
        -1,651,000 914,000 902,000 -355,000 -1,527,000 1,006,000 463,000 -2,642,000 701,000 -123,000 342,000 -1,618,000 -398,000 2,081,000 1,204,000 -1,838,000 -1,757,000 2,236,000 -171,000 1,406,000 -1,124,000 769,000 -4,182,000 60,000 1,867,000 2,852,000 -1,823,000 -678,000 1,166,000 -1,798,000 -1,278,000 2,230,000 1,807,000 -4,693,000 1,243,000 1,284,000 -2,121,000 1,689,000 -3,191,000 1,146,000 -2,780,000 498,000 1,149,000 103,000                                           
          net cash from operating activities
        44,765,000 41,095,000 45,579,000 34,424,000 66,220,000 54,145,000 56,629,000 71,499,000 77,786,000 78,942,000 81,350,000 72,900,000 68,888,000 82,496,000 63,123,000 52,331,000 55,161,000 30,059,000 13,384,000 23,200,000 13,155,000 24,323,000 19,935,000 31,861,000 19,390,000 41,375,000 53,593,000 22,953,000 81,375,000 33,405,000 54,344,000 19,799,000 46,352,000 25,724,000 34,858,000 20,205,000 25,241,000 38,259,000 25,033,000 19,428,000 42,074,000 55,240,000 50,638,000 55,472,000 53,659,000 57,458,000 61,008,000 38,630,000 57,559,000 65,866,000 79,736,000 43,913,000 77,536,000 61,865,000 82,522,000 49,485,000 87,252,000 79,642,000 91,646,000 47,034,000 83,034,000 62,107,000 71,672,000 41,881,000 71,870,000 38,120,000 57,127,000 43,552,000 70,813,000 58,273,000 61,667,000 39,203,000 53,224,000 38,325,000 45,861,000 30,743,000 36,299,000 33,384,000 32,510,000 36,650,000 29,734,000 34,493,000 31,378,000 26,070,000  30,791,000 
          cash flows from investing activities
                                                                                              
          proceeds from asset sales and disposals
        906,000 730,000 247,000 37,000 1,000 4,643,000 165,000 2,002,000 855,000 5,000 101,000 384,000 353,000   74,000 116,000 59,000 116,000   -111,000                                                              
          return of long-term contract receivable
        743,000 728,000 714,000 700,000 686,000 673,000 659,000 647,000 633,000 622,000 610,000 598,000 585,000 575,000   541,000 540,000 541,000 541,000 660,000 332,000 858,000 272,000  459,000 451,000 441,000 455,000 1,590,000 529,000 487,000                                                       
          capital expenditures
        -8,000 -2,000 -59,000  
          free cash flows
        44,765,000 41,095,000 45,579,000 34,424,000 66,220,000 54,145,000 56,629,000 71,499,000 77,786,000 78,942,000 81,342,000 72,898,000 68,829,000 82,496,000 63,123,000 52,331,000 55,161,000 30,059,000 13,384,000 23,200,000 13,155,000 24,323,000 19,935,000 31,861,000 19,390,000 41,375,000 53,593,000 22,953,000 81,375,000 33,405,000 54,344,000 19,799,000 46,352,000 25,724,000 34,858,000 20,205,000 25,241,000 38,259,000 25,033,000 19,428,000 42,074,000 55,240,000 50,638,000 55,472,000 53,659,000 57,458,000 61,008,000 38,630,000 57,559,000 65,866,000 79,736,000 43,913,000 77,536,000 61,865,000 82,522,000 49,485,000 87,252,000 79,642,000 91,646,000 47,034,000 83,034,000 62,107,000 71,672,000 41,881,000 71,870,000 38,120,000 57,127,000 43,552,000 70,813,000 58,273,000 61,667,000 39,203,000 53,224,000 38,325,000 45,861,000 30,743,000 36,299,000 33,384,000 32,510,000 36,650,000 29,734,000 34,493,000 31,378,000 26,070,000  30,791,000 
          net cash from investing activities
        743,000 1,634,000 1,444,000 947,000 723,000 674,000 5,302,000 812,000 2,635,000 1,477,000 607,000 697,000 910,000 869,000   541,000 614,000 657,000 600,000 777,000 332,000 365,000 206,000 186,000 6,445,000 654,000 307,000 194,442,000 -1,981,000 -1,660,000 -173,000 -103,000 2,775,000 2,910,000 -2,039,000 6,484,000 120,892,000 1,423,000 38,016,000 -5,819,000 -1,931,000 -10,671,000 -11,850,000 -510,809,000 -4,901,000 -3,286,000 -1,507,000 -21,618,000 346,000 10,874,000 -292,367,000 -36,026,000 -23,942,000 -26,030,000 -126,735,000 -12,754,000 -3,741,000 -13,709,000 -84,884,000 -56,108,000 -2,175,000 -66,363,000 -46,150,000 -3,768,000 -19,345,000 -96,798,000 124,000 -2,498,000 -4,654,000 -2,800,000 -33,326,000 -7,361,000 -19,887,000 -19,060,000 -156,636,000 -54,401,000 -15,609,000 -31,068,000 -29,578,000 -54,580,000 -21,544,000  -401,000 
          cash flows from financing activities
                                                                                              
          debt borrowings
        13,000,000 33,700,000 15,000,000 23,000,000 40,493,000 89,357,000 33,800,000 50,000,000 70,834,000 94,200,000                                                                         
          debt repayments
        -49,331,000 -32,000,000 -37,500,000 -37,000,000 -70,332,000 -36,000,000 -19,000,000 -55,696,000 -86,335,000 -25,000,000 -61,365,000 -89,696,000 -141,731,000 -60,494,000 -120,474,000 -16,697,000 -20,335,000 -2,365,000 -16,696,000 -20,335,000 -6,780,000 -2,365,000 -16,696,000 -20,335,000 -8,277,000                                                             
          distributions to common unitholders and the general partner
        -10,054,000 -10,055,000 -10,055,000 -26,276,000 -9,987,000 -9,986,000 -9,987,000 -42,186,000 -9,670,000 -9,669,000 -9,669,000 -40,900,000 -9,571,000 -9,571,000 -9,570,000 -5,672,000 -5,672,000 -5,671,000 -5,672,000 -5,630,000                                                                   
          distributions to preferred unitholders
            -1,605,000 -2,643,000 -2,150,000 -2,150,000 -4,437,000 -7,982,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -3,980,000 -3,921,000 -3,864,000 -3,806,000 -3,750,000 -7,500,000 -7,613,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,500,000 -7,765,000 -3,825,000 -3,769,000                                                     
          redemptions of preferred units
                                                                                              
          warrant settlements
            -10,000,000 -55,689,000                                                                               
          net cash from financing activities
        -46,386,000 -42,054,000 -47,555,000 -34,939,000 -67,399,000 -56,259,000 -40,581,000 -73,310,000 -86,843,000 -72,738,000 -88,882,000 -95,033,000 -91,644,000 -81,784,000 -140,266,000 -52,261,000 -39,171,000 -9,592,000 -12,900,000 -26,823,000 -29,715,000 -19,910,000 -9,978,000 -29,826,000 -33,474,000 -21,432,000 -98,179,000 -99,583,000 -133,174,000 -21,012,000 -20,861,000 -28,301,000 -137,666,000 51,962,000 -109,930,000 54,408,000 -83,745,000 -90,151,000 -55,162,000 -57,120,000 -45,638,000 -19,678,000 -45,717,000 -60,423,000 429,100,000 -44,444,000 -42,535,000 -74,810,000 -43,103,000 -71,741,000 -61,559,000 175,183,000 -14,505,000 -37,478,000 -41,922,000 -30,268,000 -9,688,000 -71,494,000 -1,240,000 11,352,000 -3,660,000 -66,102,000 10,245,000 -15,509,000 -46,348,000 -39,390,000 -76,741,000 64,427,000 -45,421,000 -51,817,000 -50,879,000 -40,424,000 -15,934,000 -31,041,000   125,597,000 29,181,000 -31,649,000 14,095,000 -1,922,000 18,784,000 -27,721,000 474,000  -15,663,000 
          net increase in cash and cash equivalents
        -878,000 675,000 -532,000 432,000 -456,000 -1,440,000      -21,436,000 -21,846,000   70,000 16,531,000 21,081,000 1,141,000 -3,023,000 -15,783,000 4,745,000 10,322,000 2,241,000      10,412,000 31,823,000 -8,675,000 -91,417,000 80,461,000 -72,162,000 72,574,000 -52,020,000   324,000 -9,383,000            27,005,000 445,000   64,810,000       -19,778,000 21,754,000 -20,615,000 -19,614,000 11,181,000 25,516,000 3,958,000   3,964,000 -77,000 -1,163,000 -10,427,000  8,164,000 -14,748,000 19,677,000  -1,303,000 3,657,000 5,000,000  14,727,000 
          cash and cash equivalents at beginning of period
        30,444,000 11,989,000 39,091,000  135,520,000     98,265,000      29,827,000 40,371,000 51,773,000 50,076,000 92,513,000 149,424,000 214,922,000 95,506,000 82,634,000 89,928,000 58,341,000 66,044,000  47,691,000  42,103,000  
          cash and cash equivalents at end of period
        -878,000 675,000 -532,000 30,876,000 -456,000 -1,440,000 21,350,000 10,990,000 -6,422,000 7,681,000 -6,925,000 17,655,000 -21,846,000 1,581,000 -76,234,000 135,590,000 16,531,000 21,081,000 1,141,000 96,767,000 -15,783,000 4,745,000 10,322,000 100,506,000      10,412,000 31,823,000 21,152,000 -91,417,000 80,461,000 -72,162,000 112,945,000 -52,020,000 69,000,000 -28,706,000 52,097,000 -9,383,000 33,631,000 -5,750,000 33,275,000 -28,050,000 8,113,000 15,187,000 54,826,000 -7,162,000 -5,529,000 29,051,000 76,153,000 27,005,000 445,000 14,570,000 107,404,000 64,810,000 4,407,000 76,697,000 69,008,000 23,266,000 -6,170,000 15,554,000 62,856,000 21,754,000 -20,615,000 -19,614,000 101,109,000 25,516,000 3,958,000 6,134,000 54,320,000 3,964,000 -77,000 -1,163,000 55,617,000  8,164,000 -14,748,000 67,368,000  -1,303,000 3,657,000 47,103,000  14,727,000 
          supplemental cash flow information:
                                                                                              
          cash paid for interest
        1,516,000 1,413,000 2,725,000 2,371,000 3,986,000 3,800,000 4,823,000 2,843,000 4,372,000 3,050,000 3,960,000 2,474,000 6,764,000 1,729,000 15,128,000 1,644,000  1,898,000 16,611,000 2,320,000                                                                   
          equity earnings from unconsolidated investment
         2,390,000 -2,526,000 -4,610,000 -931,000 -8,109,000 -3,645,000 -5,450,000 -14,764,000 -12,401,000 -26,978,000 -19,254,000 -15,759,000 -14,556,000 -14,643,000 -14,837,000 -10,625,000 -6,672,000 -2,601,000 -1,973,000 -5,528,000 -1,986,000 3,058,000 -6,272,000 -10,256,000 -13,818,000 -11,333,000 -11,682,000 -13,320,000 -8,836,000 -16,529,000 -9,621,000 -12,781,000 -8,993,000 -8,389,000 -10,294,000 -9,319,000 -10,753,000 -10,188,000 -9,801,000 -13,179,000 -12,617,000 -11,599,000 -12,523,000                                           
          redemption of preferred units
             -31,666,000    -50,001,000 -80,248,000 -48,085,000                                                                           
          loss on extinguishment of debt
                    3,933,000 2,484,000                                                                     
          redemption of preferred units paid-in-kind
                    -19,579,000                                                                     
          net decrease in cash and cash equivalents
               -999,000  7,681,000                                 -5,750,000 -16,801,000            -107,518,000   76,697,000 -26,498,000  -6,170,000          -4,021,000               
          acquisition of non-controlling interest in brp
                                                                                            
          non-cash investing and financing activities:
                                                                                              
          preferred unit distributions paid-in-kind
                         3,922,000 3,863,000 3,806,000                                                                   
          warrant settlement
                                                                                              
          cash flows from operating activities of continuing operations
                                                                                              
          net cash from operating activities of continuing operations
                        55,161,000 30,059,000 13,384,000 23,200,000 13,155,000 24,323,000 19,935,000 30,155,000 19,394,000 41,734,000 53,359,000 22,832,000 70,265,000 33,427,000 54,379,000 20,211,000 46,444,000 25,800,000 35,105,000 20,489,000 26,096,000 35,901,000                                                 
          net cash from operating activities of discontinued operations
                            1,706,000 -4,000 -359,000 234,000 121,000 11,110,000 -22,000 -35,000 -412,000 -92,000 -76,000 -247,000 -284,000 -855,000 2,358,000                                                 
          net cash from investing activities of continuing operations
                        541,000 614,000 657,000 600,000 776,000 332,000 365,000 272,000 259,000 6,567,000 698,000 697,000 11,421,000 -1,981,000 -1,660,000 -173,000 -103,000 2,771,000 2,737,000 -2,068,000 6,433,000 10,257,000                                                 
          net cash from investing activities of discontinued operations
                            1,000 -66,000 -73,000 -122,000 -44,000 -390,000     4,000 173,000 29,000 51,000 110,635,000                                                 
          contributions from discontinued operations
                                                                                              
          net cash from financing activities of continuing operations
                        -39,171,000 -9,592,000 -12,900,000 -26,823,000 -29,714,000 -19,910,000 -9,978,000 -28,186,000 -33,551,000 -21,913,000 -97,989,000 -99,852,000 63,804,000 -21,034,000 -20,896,000 -28,713,000 -137,758,000 51,890,000 -110,004,000 54,153,000 -84,550,000 24,843,000                                                 
          net cash from financing activities of discontinued operations
                            -1,000 -1,640,000 77,000 481,000 -190,000 269,000 -196,978,000 22,000 35,000 412,000 92,000 72,000 74,000 255,000 805,000 -114,994,000                                                 
          cash and cash equivalents of continuing operations at beginning of period
                        99,790,000             40,371,000                                                 
          plant, equipment, mineral rights and other funded with accounts payable or accrued liabilities
                           992,000 23,000 23,000                                                                 
          adjustments to reconcile net income to net cash from operating activities of continuing operations:
                                                                                              
          income from discontinued operations
                                -750,000 -7,000   -17,759,000                                                          
          acquisition of mineral rights
                                               -2,725,000 -4,740,000 -6,818,000 -12,333,000 -16,788,000                                           
          contributions from (to) discontinued operations
                            1,000 1,640,000    -269,000                                                           
          distributions from unconsolidated investment in excess of cumulative earnings
                                    2,097,000                                                       
          distributions to common unitholders and general partner
                            -5,630,000 -5,630,000 -5,630,000 -5,630,000 -5,630,000 -16,265,000 -5,625,000 -5,623,000 -5,623,000 -5,623,000 -5,617,000 -5,617,000 -5,616,000 -5,619,000 -5,615,000                                                   
          debt issuance costs and other
                                -9,000 -25,000 -26,412,000 10,000 754,000 -241,000            -754,000                                             
          cash and cash equivalents of discontinued operations at beginning of period
                                                                                            
          cash and cash equivalents of continuing operations at end of period
                                        -91,417,000 80,461,000 -72,162,000 112,945,000 -52,020,000 71,000,000                                                 
          less: cash and cash equivalents of discontinued operations at end of period
                                                                                              
          cash paid during the period for interest
                            17,118,000 2,490,000 17,183,000 3,039,000           15,029,000 19,851,000    13,812,000 30,576,000 13,743,000 29,830,000 14,344,000 23,889,000 13,131,000 24,432,000 14,703,000 9,475,000 16,631,000 12,784,000 16,301,000 10,729,000 16,137,000 10,684,000 16,292,000 10,579,000 16,215,000 3,400,000 17,459,000 3,273,000 17,222,000 3,370,000 17,700,000 3,394,000 17,556,000 3,480,000 10,280,000 3,556,000 9,729,000 4,292,000 10,158,000 4,392,000 9,752,000 3,979,000 7,648,000 5,032,000 2,841,000 4,261,000 1,600,000 4,320,000 427,000 4,575,000 137,000 4,452,000 224,000 
          loss from discontinued operations
                                   46,000   34,000 14,000   -133,000 207,000 323,000 -7,112,000                                                 
          debt modification expense
                                        132,000 7,807,000                                                   
          return of long-term contract receivables
                                         600,000                                                     
          proceeds from issuance of preferred units and warrants
                                                                                              
          net increase in cash, cash equivalents and restricted cash
                                -13,898,000 26,388,000                                                             
          cash, cash equivalents and restricted cash of continuing operations at beginning of period
                                206,030,000                                                           
          cash, cash equivalents and restricted cash at beginning of period
                                206,030,000                                                           
          cash, cash equivalents and restricted cash at end of period
                                -13,898,000 26,388,000 -43,932,000 129,707,000                                                           
          cash, cash equivalents and restricted cash of continuing operations at end of period
                                -13,898,000 26,388,000 -43,932,000 129,707,000                                                           
          cash paid during the period for interest of continuing operations
                                22,327,000 3,225,000 9,623,000 23,422,000                                                           
          issuance of 2022 senior notes in exchange for 2018 senior notes
                                        240,638,000                                                   
          contributions to discontinued operations
                                 -481,000    -22,000 -35,000 -412,000   -74,000 -255,000                                                   
          gain on asset sales
                                  -246,000 -256,000 -1,408,000 -163,000 -210,000 -660,000 -280,000 -171,000 -3,361,000 -44,000 -1,801,000 -6,426,000 1,071,000 -21,925,000                                               
          proceeds from sale of assets
                                  247,000 256,000 1,300,000 238,000 224,000 687,000 563,000            1,413,000    10,370,000 405,000 154,000 9,775,000 14,762,000                       829,000 3,932,000       
          borrowings on revolving credit facility
                                                                                              
          repayments of loans
                                   -86,468,000 -119,986,000 -7,648,000 -7,272,000 -40,800,000 -136,027,000 -8,000,000 -97,282,000 -251,010,000 -76,967,000 -7,692,000 -47,316,000 -51,166,000                                               
          net decrease in cash, cash equivalents and restricted cash
                                   -76,323,000                                                           
          cash, cash equivalents and restricted cash of discontinued operations at beginning of period
                                                                                              
          less: cash, cash equivalents and restricted cash of discontinued operations at end of period
                                                                                              
          amortization expense—affiliate
                                                                                              
          other—affiliates
                                    -11,000                                                         
          accounts receivable—affiliates
                                    -12,000 118,000 -46,000 67,000 1,144,000 49,000 121,000 -947,000 399,000 1,559,000 -1,610,000 -661,000 586,000   3,643,000                                           
          accounts payable—affiliates
                                    1,330,000 -844,000 -641,000 1,531,000 -107,000 -272,000 -254,000 256,000 110,000 54,000 212,000 -237,000 -1,102,000 1,627,000 3,000 -14,000                                           
          accrued liabilities—affiliates
                                    400,000 -515,000                                                     
          accrued interest—affiliates
                                                                                              
          deferred revenue—affiliates
                                        -7,269,000 -2,897,000 -3,032,000 -4,130,000 -3,075,000 -985,000 -801,000 -3,462,000 801,000 -738,000                                           
          return of long-term contract receivable—affiliate
                                                                                              
          acquisition of plant and equipment and other
                                     -3,809,000 -2,413,000 -3,444,000 -1,065,000 -1,238,000 -2,903,000 -2,095,000 -977,000 -512,000 -1,698,000 -2,221,000 -1,594,000 -3,508,000                                             
          proceeds from issuance of 2022 senior notes
                                        103,688,000                                                   
          borrowings on credit facility
                                    35,000,000                                                       
          cash paid during the period for interest from continuing operations
                                    6,838,000 24,998,000 7,132,000 26,023,000 10,993,000                                                      
          plant, equipment and mineral rights funded with accounts payable or accrued liabilities
                                               811,000 1,484,000 13,000 691,000 3,761,000                                           
          other, net—affiliates
                                       -190,000 1,119,000 200,000 -999,000 887,000 145,000 636,000 -452,000 664,000 434,000 -734,000 6,000 7,000                                           
          redemption of preferred units paid in kind
                                       -8,844,000                                                       
          debt issue costs and other
                                       -275,000 -197,000 347,000 -5,779,000 -34,755,000 -1,162,000 -2,074,000 -11,660,000 -338,000                                               
          cash flows from operating activities:
                                                                                              
          amortization expense—affiliates
                                        240,000 768,000 857,000 902,000 704,000 722,000                                               
          return on earnings from unconsolidated investment
                                        12,250,000 8,992,000                                                     
          gain on reserve swap
                                                       -8,149,000                                   
          cash flows from investing activities:
                                                                                              
          return of equity from unconsolidated investment
                                        3,258,000                                                     
          return of long-term contract receivables—affiliate
                                        390,000 414,000 391,000 397,000 1,871,000 309,000                                               
          cash flows from financing activities:
                                                                                              
          proceeds from issuance of class a convertible preferred units and warrants
                                                                                              
          proceeds from loans
                                        8,000,000      75,000,000 25,000,000 635,375,000 2,000,000 20,000,000 304,020,000 43,000,000 200,000,000 45,000,000 30,000,000 26,000,000 47,000,000 50,000,000 250,000,000 85,000,000 55,000,000 4,000,000 35,000,000 46,000,000 6,000,000 22,000,000 303,000,000     23,000,000 7,000,000 18,400,000 237,000,000 151,000,000 53,000,000 50,000,000 19,000,000 88,000,000 18,000,000 
          distributions to non-controlling interest
                                                -2,082,000 -662,000                                           
          proceeds from (contributions to) discontinued operations
                                        -92,000                                                      
          cash paid during the period for interest from discontinued operations
                                                                                              
          gain from discontinued operations
                                                                                              
          proceeds from issuance of convertible preferred units and warrants
                                         242,100,000                                                   
          non-cash financing activities:
                                                                                              
          fair value adjustments for warrant liabilities
                                          -23,960,000 -16,569,000                                                   
          warrant issuance expense
                                          5,709,000                                                   
          other
                                          1,332,000 1,090,000 1,590,000 2,600,000 2,207,000 1,887,000 1,738,000 -305,000 -1,718,000 -1,010,000                                           
          other items, net—affiliates
                                              -512,000 1,119,000 819,000 -268,000 374,000 -739,000                                           
          proceeds from sale of oil and gas royalty properties
                                          4,000 -548,000 6,880,000 1,617,000                                                 
          proceeds from sale of coal and aggregates royalty properties
                                          1,288,000 139,000                                                   
          proceeds from sale of plant and equipment and other
                                          363,000 22,000 164,000 343,000 840,000 3,000 18,000 5,751,000                                             
          distributions from equity earnings from unconsolidated investment
                                           12,250,000 12,250,000 12,250,000    12,740,000 10,902,000 10,903,000                                           
          proceeds from sale of coal and aggregate royalty properties
                                                                                              
          acquisition of aggregates business
                                                                                              
          proceeds from loan—affiliate
                                                                                              
          proceeds from issuance of common units
                                                    102,376,000                                          
          capital contribution by general partner
                                                    2,733,000 160,000 255,000 92,000 1,531,000                                  
          distributions to unitholders
                                                                                              
          non-cash investing activities:
                                                                                              
          units issued for acquisition of aggregates business
                                                                                              
          change in assets and liabilities:
                                                                                              
          proceeds from sale of coal and hard mineral royalty properties
                                             8,412,000 9,802,000                                               
          distributions to partners
                                             -5,617,000 -5,616,000 -5,616,000 -5,616,000 -11,232,000 -11,232,000 -43,678,000  -39,733,000 -39,421,000 -40,192,000  -61,629,000 -61,630,000 -63,058,000  -59,727,000 -59,505,000 -62,077,000  -58,478,000 -58,422,000 -58,423,000 -58,422,000 -54,040,000 -54,039,000 -43,348,000 -43,348,000 -50,697,000 -47,370,000 -46,720,000 -45,422,000 -44,125,000 -41,529,000 -40,231,000 -38,934,000 -37,635,000 -36,338,000 -34,126,000 -25,339,000 -23,819,000 -22,299,000 -20,905,000 -20,060,000 -19,216,000 -18,371,000 -17,526,000 -16,779,000 -15,663,000 
          asset impairment
                                              -46,000 2,030,000 50,953,000 626,838,000   20,585,000   443,000 291,000     70,404,000                              
          distributions from equity earnings from unconsolidated investments
                                               12,250,000                                               
          proceeds from sale of oil and gas properties
                                               32,848,000                                               
          accrued incentive plan expenses
                                                -606,000 535,000 -677,000 -6,275,000 180,000 471,000 2,149,000 -8,065,000 2,364,000 1,139,000 2,036,000 -3,255,000 83,000 1,717,000 1,331,000 -6,592,000 1,923,000 1,116,000 1,697,000 -2,827,000 3,712,000 3,765,000 1,181,000 -2,521,000 2,169,000 840,000 2,034,000 -466,000 -2,535,000 -1,584,000 4,226,000 -3,148,000 603,000 495,000 2,562,000 -3,195,000 991,000 996,000 1,139,000 371,000 -943,000 1,389,000 1,219,000 5,000  860,000 
          proceeds from sale of mineral rights
                                                155,000 1,660,000 1,020,000 4,261,000                                           
          acquisition of equity interests
                                                        -8,000 -98,000 -40,000 -292,939,000                                   
          return of equity and other unconsolidated investments
                                                                                              
          proceeds from loans—affiliate
                                                                                              
          units issued for acquisition of aggregate operations
                                                                                              
          non-cash contingent consideration on equity investments
                                                                                              
          return on equity and other unconsolidated investments
                                                                                              
          return on long-term contract receivables—affiliate
                                                                                              
          repayment of loans
                                                 -82,692,000 -27,317,000 -41,166,000  -15,692,000 -12,317,000 -41,166,000  -306,692,000 -42,916,000 -36,622,000  -7,692,000 -7,917,000 -15,191,000  -7,693,000 -187,633,000 -15,193,000  -7,692,000 -83,350,000 -15,192,000  -7,693,000 -9,350,000 -151,192,000  -7,692,000 -9,350,000 -193,000  -400,000 -9,350,000 -226,192,000 -9,350,000 -15,000,000 -50,000,000   
          accounts receivable—affiliate
                                                                                              
          return on direct financing lease and contractual override—affiliate
                                                  1,137,000                                           
          acquisition of plant and equipment
                                                   -1,365,000 -2,247,000 -72,000                                         
          proceeds from sale of plant and equipment
                                                   905,000                                           
          non-cash interest charge
                                                    1,183,000 677,000 721,000 747,000 746,000 899,000 279,000 276,000 152,000 153,000 151,000 149,000 132,000 225,000 118,000 150,000 125,000 124,000 141,000 150,000 127,000 326,000 128,000 882,000 12,000 31,000 117,000 118,000 117,000 117,000 115,000 94,000 61,000 97,000 91,000 100,000 96,000 97,000 54,000 71,000  14,000 
          non-cash gain on reserve swap
                                                                                              
          equity and other unconsolidated investment income
                                                    -12,551,000 -9,685,000 -9,401,000 -9,779,000 -12,018,000 -7,238,000 -7,882,000 -7,048,000                                   
          distributions of earnings from unconsolidated investments
                                                    10,780,000 10,290,000 10,290,000 11,645,000 7,951,000                                     
          gain on sale of assets
                                                    -1,383,000    -10,370,000 -401,000 -150,000                                  
          change in operating assets and liabilities
                                                                                              
          inventory
                                                                                              
          other assets
                                                    -1,545,000 432,000 336,000 -18,000 -1,380,000 3,849,000 -3,251,000 266,000 -605,000 345,000 -176,000 200,000 -466,000 24,000 310,000 222,000 -647,000 501,000 -101,000 220,000 -646,000 312,000 267,000 -714,000 308,000 323,000 261,000 -705,000 326,000 336,000 221,000 -1,104,000 282,000 -25,000 268,000 -332,000 -316,000 351,000 250,000  426,000 
          accounts payable and accrued liabilities
                                                    -6,034,000 2,036,000 1,257,000 -1,670,000 1,405,000 571,000 1,094,000 -873,000 854,000 493,000 -521,000 1,083,000 641,000 698,000 662,000 -1,147,000 165,000 205,000 331,000 -233,000 10,000 104,000 148,000 -395,000 -1,931,000 18,000 680,000 -251,000 -247,000 77,000 -492,000 198,000           
          property, franchise and other taxes payable
                                                    1,775,000 -1,217,000 1,688,000 -2,537,000 2,704,000 -1,467,000 1,041,000 -2,400,000 2,350,000 -132,000 1,910,000 -2,492,000 1,817,000 -1,014,000 1,425,000 -2,838,000 1,323,000 -58,000 549,000 -1,052,000 1,674,000 -53,000 559,000 -2,138,000 1,583,000 -886,000 1,472,000 -2,462,000 1,781,000 45,000 -138,000 397,000 339,000 158,000 -708,000 403,000 1,060,000 388,000     
          acquisition of land, coal, other mineral rights and related intangibles
                                                    -339,000,000                                          
          oil and gas capital expenditures
                                                    -2,991,000 -5,144,000 -6,319,000 -1,804,000                                       
          distributions from unconsolidated investments
                                                        38,056,000 10,540,000 237,000                                   
          return on direct financing lease and contractual override
                                                    994,000 310,000 303,000 297,000 1,717,000 286,000 137,000 418,000 270,000 1,495,000                                 
          investment in direct financing lease
                                                                                              
          deferred financing costs
                                                        -148,000 -7,440,000 -1,621,000             -661,000     -6,000 -179,000 -1,107,000           
          payment of obligation related to acquisitions
                                                                -3,600,000                             
          costs associated with equity transactions
                                                    -3,812,000 -163,000 -381,000 -57,000 -233,000 -13,000 -47,000    -1,000 -108,000 -32,000                           
          distributions to non-controlling interests
                                                                                              
          net (decrease) in cash and cash equivalents
                                                      15,187,000 -37,687,000  -5,529,000 29,051,000 -73,271,000                                   
          note receivable related to sale of assets
                                                                                              
          distributions from unconsolidated affiliates
                                                                                             
          proceeds from issuance of units
                                                      9,329,000 4,513,000  75,000,000                                 
          non-controlling interest
                                                                947,000   2,290,000                         
          acquisition or construction of plant and equipment
                                                            -189,000 9,636,000 -10,128,000 -79,000 -163,000 -162,000 -1,674,000 -2,218,000   -1,157,000   -4,654,000 -2,800,000               
          distributions
                                                                                              
          purchase obligation related to reserve and infrastructure acquisitions
                                                                                              
          acquisition of land and mineral rights
                                                                                              
          repayment of obligation related to acquisitions
                                                                                             
          non-cash activities:
                                                                                              
          note receivable from sale of assets
                                                                                              
          fees associated with elimination of idrs
                                                                                              
          contributions by general partner
                                                                                             
          liability assumed in acquisitions
                                                                                             
          gains on sale of assets
                                                             -4,715,000                                 
          acquisition of land, coal and other mineral rights
                                                             -40,010,000 -26,727,000 -67,726,000  -8,141,000 -14,546,000 -84,822,000  -765,000 -64,261,000 -46,150,000  -19,345,000 -95,641,000               -21,544,000   
          acquisition of contracts
                                                                                             
          obligation related to purchase of reserves and infrastructure
                                                                 -1,925,000 6,025,000                          
          note receivable from sale of asset
                                                                                              
          acquisition of contracts – affiliate
                                                               -48,881,000                               
          equity issued for acquisitions
                                                                                            
          assets contributed by general partner for acquisitions
                                                                                              
          adjustments to reconcile net income to net
                                                                                              
          cash from operating activities:
                                                                                              
          debt issuance costs
                                                                 -1,722,000                             
          capital contribution
                                                                                              
          fees associated with the elimination of the idr’s
                                                                                              
          mineral rights to be received
                                                                                             
          liability associated with an acquisition
                                                                                              
          disposition of assets
                                                                  1,000,000 100,000                           
          retirement of obligation related to acquisitions
                                                                     -6,200,000 -2,969,000                       
          change in restricted accounts
                                                                                              
          retirement of purchase obligation related to reserves and infrastructure
                                                                                              
          costs associated with unit issuance
                                                                                              
          liability assumed from acquisitions
                                                                                              
          costs associated with issuance of units
                                                                                            
          fees associated with the elimination of the idrs
                                                                                              
          obligation related to purchase of coal reserves and infrastructure
                                                                       4,477,000  14,802,000 59,220,000                   
          purchase obligation related to reserve and infrastructure acquisition
                                                                                              
          loss from disposition of assets
                                                                                             
          retirement of obligation related to purchase of coal reserves and infrastructure
                                                                          -20,000,000 -40,000,000                   
          equity issued for business combinations
                                                                                              
          assets contributed by general partner in business combination
                                                                                              
          liability assumed in business combination
                                                                                39,000 1,950,000           
          equity issued for assets purchased
                                                                                              
          utility improvement obligation acquired
                                                                                              
          acquisition of land, coal and other mineral rights.
                                                                                              
          acquisition or construction of plant and equipment.
                                                                                              
          cash placed in restricted accounts
                                                                                 74,000 -72,000 -6,242,000           
          contribution by general partner
                                                                                 330,000 2,315,000           
          equity issued in business combinations
                                                                                              
          current payable assumed in a business combination
                                                                                              
          cash placed in restricted account
                                                                                              
          fractional units redeemed upon conversion of subordinated units
                                                                                              
          gain on sale of timber assets
                                                                                              
          acquisition of land, plant and equipment, coal and other mineral rights
                                                                                 -7,435,000 -18,661,000 -13,972,000 -158,926,000 -54,401,000 -16,438,000 -35,000,000       
          proceeds from sale of timber assets
                                                                                              
          units issued in business combinations
                                                                                 7,119,000 343,622,000           
          current payable assumed in business combination
                                                                                   1,154,000           
          net cash from or (used in) financing activities
                                                                                   -22,110,000           
          loss on early extinguishment of debt
                                                                                              
          proceeds from sale of 5,250,000 common units, net of transaction costs
                                                                                            
          redemption of 2,616,752 common units
                                                                                              
          redemption of fractional units upon conversion of subordinated units
                                                                                              
          net increase in cash
                                                                                              
          cash at beginning of period
                                                                                              
          cash at end of period
                                                                                              
          gain from sale of assets
                                                                                     -458,000 -2,176,000       
          loss on sale of oil and gas properties
                                                                                              
          acquisition of coal and other mineral rights
                                                                                              
          settlement of hedge included in accumulated other comprehensive loss
                                                                                              
          depletion and amortization
                                                                                         8,221,000 8,625,000 7,879,000  8,077,000 
          redemption of 2,616,752 common units net of transaction costs
                                                                                              
          redemption of 2,616,752 common units from arch coal, inc., net of transaction costs
                                                                                             
          property and franchise taxes payable
                                                                                           1,000  136,000 
          proceeds from sale of properties
                                                                                              
          proceeds from financing
                                                                                              
          repayment of notes payable
                                                                                              
          repayment of debt
                                                                                              
          cash placed in (returned from) escrow
                                                                                              
          non-cash transactions:
                                                                                              
          issuance of note payable for reversionary interest
                                                                                              
          contributions by general partner and sponsors
                                                                                              
          proceeds from initial sale of common units net of transaction costs
                                                                                              
          proceeds from sale of common units to gnp and ngcc
                                                                                              
          net assets contributed by partners
                                                                                              
          excess of cost over net book value of arch properties
                                                                                              
          deferred revenue assumed on acquisition of property
                                                                                              
          1.
                                                                                              
          settlement of hedge included in other comprehensive loss
                                                                                              
          cash held in escrow
                                                                                              
          adjustments to reconcile net income to net cash provided by operating activities:
                                                                                              
          contributions by sponsors
                                                                                              
          proceeds from sale of common units to gnp and ngcc distributions to partners
                                                                                              
          •