7Baggers

Arch Resources, Inc
(NYSE:ARCH) 

ARCH stock logo

Arch Resources, Inc. produces and sells thermal and metallurgical coal from surface and underground mines. As of December 31, 2020, the company operated seven active mines. It also owned or controlled primarily through long-term leases approximately 28,292 acres of coal land in Ohio; 1,060 acres of ...

Founded: 1969
Full Time Employees: 3,400
Sector: Energy
Industry: Thermal Coal

Share this website to your friends
• Market Cap:
• Exchange:
• Shs Outstanding:
• Employees:
• Beta:
• Return on Equity (ROE) ttm:
• Return on Assets (ROA) ttm:
• EPS ttm:
• Book value per Share:
• Cash per Share:
• Current ast per Share:
• P/E ttm:
• P/E forward:
• P/E ttm high:
• P/E ttm low:
• P/S ttm:
• P/B ttm:
• P/FCF ttm:
• PEG ratio:
• Cash Ratio ttm:
• Quick Ratio ttm:
• Current Ratio ttm:
• Gross Mgn ttm:
• EBITDA Mgn ttm:
• Operating Mgn ttm:
• Net Income Mgn ttm:
• Trailing Div yield:
• Forward Div yield:
• Payout Ratio ttm:
• Ex-Dividend date:
• Target Price High:
• Target Price Low:
• Target Price Mean:
• Number of Analysts:
• Debt Ratio ttm:
• Debt to Equity ttm:
• Total Net Debt:
At a glance:
Bull Thesis:
Bear Thesis:
Main Competitors:
Moat:
Income Statements:
Quarterly
Annual
    Unit: USD2024-09-30 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 2018-09-30 2018-06-30 2018-03-31 2017-12-31 2017-09-30 2017-06-30 2017-03-31 2016-10-02 2016-09-30 2016-06-30 2016-03-31 2015-12-31 2015-09-30 2015-06-30 2015-03-31 2014-06-30 2014-03-31 2013-09-30 2013-06-30 2013-03-31 2012-09-30 2012-06-30 2012-03-31 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 
                                                                    
      ​
                                                                    
      revenues
    617,899,000 608,751,000 680,190,000 774,017,000 744,601,000 757,294,000 869,931,000 859,464,000 863,835,000 1,133,358,000 867,936,000 805,697,000 594,412,000 450,389,000 357,543,000 360,578,000 382,261,000 319,521,000 405,232,000 549,480,000 619,467,000 570,222,000 555,183,000 633,180,000 592,349,000 575,295,000 560,244,000 613,538,000 549,866,000 600,975,000 -823,021,000 550,305,000 420,298,000 428,106,000 563,249,000 688,544,000 644,462,000 677,005,000 713,776,000 735,971,000 791,269,000 766,332,000 825,502,000 1,087,618,000 1,063,538,000 1,039,651,000 1,198,673,000                  
      costs, expenses and other operating
                                                                    
      cost of sales
                       492,454,000 491,004,000 451,088,000 438,471,000 482,029,000 474,388,000 454,780,000 451,221,000 495,424,000 435,038,000 461,410,000 -818,141,000 450,427,000 419,042,000 419,316,000 537,667,000 540,192,000 566,252,000 562,322,000 622,137,000 686,314,000 688,712,000 656,198,000 710,573,000 896,809,000 881,259,000 850,871,000 952,850,000                  
      depreciation, depletion and amortization
                       29,856,000 30,402,000 26,524,000 25,273,000 31,775,000 30,549,000 29,703,000 27,928,000 31,914,000 30,701,000 31,921,000 -158,977,000 69,423,000 58,459,000 63,699,000 73,134,000 103,965,000 97,372,000 104,874,000 102,464,000 104,423,000 106,323,000 111,085,000 118,868,000 126,838,000 132,868,000 139,966,000 123,026,000 95,183,000 83,537,000 95,931,000 92,857,000 87,759,000 88,519,000 88,622,000 71,468,000 68,477,000 73,041,000 75,668,000 72,185,000 71,953,000 73,042,000 67,824,000 58,628,000 57,990,000 
      accretion on asset retirement obligations
                       5,137,000 5,137,000 5,137,000 5,137,000 6,992,000 6,993,000 6,992,000 7,383,000 7,580,000 7,623,000 7,623,000                                   
      selling, general and administrative expenses
                       21,917,000 24,566,000 25,209,000 24,089,000 22,909,000 24,756,000 25,948,000 23,100,000 21,052,000 22,146,000 20,523,000 -36,507,000 20,498,000 19,019,000 19,826,000 26,179,000 25,731,000 24,268,000 22,605,000 29,931,000 29,136,000 28,800,000 34,302,000 33,209,000 33,266,000 35,178,000 30,861,000 33,276,000 29,039,000 30,435,000 28,668,000 26,999,000 35,344,000 27,166,000 27,017,000 24,029,000 21,627,000 25,114,000 26,184,000 22,235,000 33,022,000 25,680,000 24,561,000 18,868,000 22,030,000 
      merger related costs
                                                                    
      severance costs related to voluntary separation plan
                                                                    
      other operating income
                       -9,869,000 -4,254,000 -3,239,000 -1,650,000 -7,070,000 -7,318,000 -6,932,000 -16,175,000 -8,236,000 -3,549,000 -2,310,000 9,917,000 -2,476,000 -10,561,000  11,646,000  7,403,000 9,086,000           -1,116,000 -4,720,000 -7,221,000 -4,392,000 -3,391,000 -10,895,000 -15,617,000 -6,889,000 -5,635,000 -3,115,000 1,533,000 -4,131,000 332,000 -3,163,000 -4,603,000 -17,549,000 
      income from operations
                       -6,960,000 106,481,000 66,570,000 76,779,000 82,886,000 44,595,000 65,167,000 50,951,000 72,489,000 42,692,000 66,264,000 303,256,000 11,795,000 -110,521,000           135,960,000  54,081,000 92,266,000 102,817,000 102,238,000 86,938,000 98,347,000 106,499,000 32,200,000 29,495,000 48,338,000 7,309,000 38,572,000 87,238,000 87,751,000 168,950,000 116,450,000 75,080,000 49,824,000 53,850,000 
      yoy
                       -108.40% 138.77% 2.15% 50.69% 14.34% 4.46% -1.66% -83.20% 514.57% -138.63%               32.23%  -37.79% -6.18% -3.46% 217.51% 194.76% 103.46% 1357.09% -16.52% -66.19% -44.91% -95.67% -66.88% 16.19% 76.12% 213.74%     
      qoq
                       -106.54% 59.95% -13.30% -7.37% 85.86% -31.57% 27.90% -29.71% 69.80% -35.57% -78.15% 2471.06% -110.67%              -41.39% -10.26% 0.57% 17.60% -11.60% -7.65% 230.74% 9.17% -38.98% 561.35% -81.05% -55.79% -0.58% -48.06% 45.08% 55.10% 50.69% -7.48%  
      interest expense
                       -3,629,000 -4,049,000 -4,375,000 -4,432,000 -5,179,000 -5,050,000 -5,395,000 -5,505,000 -5,972,000 -6,003,000 -9,425,000 124,647,000 -46,164,000 -45,273,000                -34,580,000 -34,643,000 -37,698,000 -35,125,000 -35,083,000 -35,466,000 -29,791,000 -20,657,000 -20,018,000 -19,911,000 -17,019,000 -18,721,000 -20,488,000 -21,723,000 -17,151,000 -18,733,000 
      interest and investment income
                       1,751,000 3,709,000 2,088,000 2,143,000 1,801,000 1,552,000 1,273,000 560,000 720,000 842,000 527,000 -2,166,000 582,000 933,000 1,138,000 423,000 672,000 962,000 2,373,000 2,036,000 1,843,000 697,000 1,216,000 2,836,000                      
      income before nonoperating expenses
                       -8,838,000 106,141,000 64,283,000 74,490,000 79,508,000 41,097,000 61,045,000 46,006,000 67,237,000 37,531,000 57,366,000 425,737,000 -33,787,000 -154,861,000                                
      nonoperating expense
                                                                    
      non-service related pension and postretirement benefit credits
                                                                    
      net income resulting from early retirement of debt
                                                                    
      income before income taxes
                       -8,811,000 107,116,000 62,931,000 72,811,000 77,977,000 39,940,000 59,441,000 46,500,000 66,708,000 37,479,000 52,508,000 473,241,000 -54,691,000 -176,132,000           61,709,000   13,704,000 11,583,000 68,404,000 52,856,000 54,800,000 71,997,000 -2,545,000 -5,633,000 18,946,000 -12,931,000 25,022,000 78,053,000 70,967,000 150,697,000 96,387,000 54,173,000 32,380,000 35,152,000 
      (benefit from) benefit from income taxes
                                                                    
      net income
    -6,221,000 14,833,000 55,953,000 114,886,000 73,691,000 77,353,000 198,108,000 470,471,000 181,007,000 407,563,000 271,872,000 226,606,000 89,143,000 27,866,000 -6,042,000 -78,525,000 -191,467,000 -49,324,000 -25,299,000 -8,551,000 106,769,000 62,840,000 72,741,000 123,192,000 43,306,000 59,985,000 81,271,000 68,351,000 37,160,000 51,668,000 467,459,000 -51,421,000 -175,887,000 -206,702,000 -570,193,500 -1,999,476,000 -168,103,000 -113,195,000 -96,860,000 -124,139,000    45,751,000  1,409,000 19,287,000 11,397,000 55,874,000 48,031,000 46,859,000 66,274,000 -1,770,000 1,552,000 25,216,000 -15,161,000 30,572,000 62,338,000 97,848,000 112,997,000 81,147,000 81,373,000 27,280,000 37,552,000 
      yoy
    -108.44% -80.82% -71.76% -75.58% -59.29% -81.02% -27.13% 107.62% 103.05% 1362.58% -4599.70% -388.58% -146.56% -156.50% -76.12% 818.31% -279.33% -178.49% -134.78% -106.94% 146.55% 4.76% -10.50% 80.23% 16.54% 16.10% -82.61% -232.92% -121.13% -125.00% -181.98% -97.43% 4.63% 82.61% 488.68% 1510.68%    -371.34%    301.43%  -97.07% -58.84% -82.80% -3256.72% 2994.78% 85.83% -537.13% -105.79% -97.51% -74.23% -113.42% -62.33% -23.39% 258.68% 200.91%     
      qoq
    -141.94% -73.49% -51.30% 55.90% -4.73% -60.95% -57.89% 159.92% -55.59% 49.91% 19.98% 154.21% 219.90% -561.20% -92.31% -58.99% 288.18% 94.96% 195.86% -108.01% 69.91% -13.61% -40.95% 184.47% -27.81% -26.19% 18.90% 83.94% -28.08% -88.95% -1009.08% -70.76% -14.91% -63.75% -71.48% 1089.44% 48.51% 16.86% -21.97%       -92.69% 69.23% -79.60% 16.33% 2.50% -29.30% -3844.29% -214.05% -93.85% -266.32% -149.59% -50.96% -36.29% -13.41% 39.25% -0.28% 198.29% -27.35%  
      net income per common share
                                                                    
      basic earnings per share
    -0.34 0.82 3.05 6.25 4.05 4.2 11.05 26.7 9.84 24.26 17.6 14.78 5.83 1.82  -5.17 -12.64                                                
      diluted earnings per share
    -0.34 0.81 2.98 6.08 3.91 4.04 10.02 22.88 8.68 19.3 12.89 12.71 4.92 1.66  -5.17 -12.64                                                
      weighted-average shares outstanding
                                                                    
      basic weighted-average shares outstanding
    18,097 18,097 18,347 18,233 18,187 18,406 17,924 17,136 18,396 16,801 15,448 15,318 15,302 15,294 15,283 15,153 15,147 15,145,000 15,139,000 16,218,000 15,736,000 16,543,000 17,494,000 19,250,000 20,156,000 20,901,000 23,725,000 23,580,000 24,659,000 25,008,000 25,002,000                211,337,000 174,244,000 162,576,000 162,398,000 162,391,000 162,388,000 162,372,000 150,963,000 155,622,000 142,815,000 142,789,000 143,604,000 144,035,000 144,120,000 143,497,000 142,518,000 142,627,000 142,369,000 
      diluted weighted-average shares outstanding
    18,097 18,295 18,775 19,183 18,840 19,135 19,784 20,985 20,908 21,452 21,271 17,579 18,105 16,756 15,283 15,153 15,147 15,145,000 15,139,000 17,298,000 16,852,000 17,781,000 18,599,000 20,208,000 21,036,000 21,875,000 24,240,000 24,135,000 25,082,000 25,408,000 25,469,000                211,974,000 175,272,000 163,773,000 163,210,000 163,174,000 163,130,000 162,372,000 151,272,000 156,005,000 142,815,000 142,848,000 144,416,000 144,898,000 145,049,000 144,596,000 144,019,000 144,151,000 143,819,000 
      dividends declared per common share
    0.25 1.11 1.65 2.383 3.97 2.45 3.11 3.59 8.11 0.25     0.125   500 337.5 450 450 450 400 400 400 175 350 350           10 30 30 30 30 30 110 110 110 100 100 100 100 90 90 90 90 90 90 90 90 70 70 70 70 
      non-service related pension and postretirement benefit (costs) credits
                       -531,750 975,000 -1,336,000   68,000                                        
      benefit from income taxes
                       -260,000 347,000 91,000 70,000 -45,215,000 -3,366,000 -544,000 -34,771,000 -1,643,000 319,000 840,000 5,782,000 -3,270,000 -245,000           15,958,000    186,000 12,530,000 4,825,000 7,941,000 5,723,000 -775,000 -7,185,000 -6,270,000 2,230,000 -5,550,000 15,715,000 -26,881,000 37,700,000 15,240,000 -27,200,000 5,100,000 -2,400,000 
      change in fair value of coal derivatives
                                                                -30,558,000    
      interest income
                                               1,459,000 1,088,000 1,021,000 840,000 755,000 746,000 561,000 927,000 623,000 338,000 338,000 399,000 417,000 6,468,000 10,726,000 235,000 468,000 425,000 963,000 513,000 453,000 
      change in fair value of coal derivatives and coal trading activities
                       1,250,000 1,530,000 -8,400,000 -12,981,000 10,418,000 15,138,000 -3,414,000 4,477,000 1,028,000 863,000 854,000 -2,460,000 488,000 1,158,000 1,210,000   1,211,000 1,220,000  914,000 9,753,000  1,308,000 5,840,000   8,360,000 2,672,000 -1,784,000 -3,372,000 1,832,000 4,587,000 5,877,000 -1,728,000 -3,342,000 -6,458,000 -528,000 10,243,000 18,382,000 -53,160,000     
      nonoperating expenses
                                                                    
      non-service related pension and postretirement benefit costs
                          -1,766,000 -971,000  -1,303,000                                       
      costs related to proposed joint venture with peabody energy
                       7,044,000 3,754,000 3,018,000                                           
      asset impairment and restructuring
                                                                    
      gain on property insurance recovery related to mountain laurel longwall
                                                                    
      gain on divestitures
                                                                    
      nonoperating (expenses) income
                                                                    
      reorganization items
                       17,750  -16,000 87,000 -560,000 -740,000 -301,000 -723,000 -43,000 -21,000 -2,828,000 -11,512,500 -20,904,000 -21,271,000                                
      basic loss per share
                  -0.4                                                  
      diluted loss per share
                  -0.4                                                  
      asset impairment
                                                                    
      (gain) loss on divestitures
                                                                    
      preference rights lease application settlement income
                        -39,000,000                                            
      basic earnings per common share
                     -3,260 -1,670 -190 6,790 3,800 4,160 6,400 2,150 2,870 3,610 2,900 1,510 2,070           -980  -330 220 -2,050 10 90 60 340 300 290 410 -10  160 -110 210 440 680 780 570 570 190 260 
      diluted earnings per common share
                     -3,260 -1,670 -140 6,340 3,530 3,910 6,100 2,060 2,740 3,520 2,830 1,480 2,030           -980  -330 220 -2,050 10 90 60 340 290 290 410 -10  160 -110 210 430 680 780 560 560 190 260 
      amortization of sales contracts
                       -357,000 -153,000 11,000 65,000 3,241,000 3,248,000 3,051,000 11,082,000 13,861,000 14,352,000 14,690,000                                   
      loss on sale of lone mountain processing, llc
                       1,076,000  4,304,000                                           
      net income resulting from early retirement of debt and debt restructuring
                            -485,000   -486,000 -31,000 -2,030,000                                   
      gain on sale of lone mountain processing, inc.
                              277,000 -21,574,000                                     
      asset impairment and mine closure costs
                                  32,316,750 46,000 43,701,000 85,520,000 488,865,000 2,120,292,000 19,146,000    200,397,000 20,482,000                       
      amortization of acquired sales contracts
                                  -182,000 104,000 1,000               1,489,000 5,944,000 9,601,000 10,038,000 5,214,000 10,753,000            
      losses from disposed operations resulting from patriot coal bankruptcy
                                      -32,971,000 149,314,000                             
      expenses related to proposed debt restructuring
                                  -553,250                                  
      basic and diluted - net income per share
                                  -5.095 -2.41 -8.26 -9.71                               
      basic and diluted weighted-average shares outstanding
                                   21,293 21,293 21,293 21,285,000 21,292,000 212,914,000 212,660,000 212,225,000 212,171,000                         
      expenses related to debt restructuring
                                                                    
      basic and diluted lps - net income
                                      -29,700 -93,910  -530 -460                          
      losses per common share
                                                                    
      basic and diluted lps
                                        -790                            
      asset impairment costs
                                          1,512,000                          
      income from continuing operations before income taxes
                                                                    
      income from continuing operations
                                                                    
      income from discontinued operations, net of tax
                                             8,145,000                       
      basic and diluted lps - income from continuing operations
                                          -460                          
      basic and diluted loss per common share
                                           -590                         
      goodwill impairment
                                                115,791,000                    
      legal contingencies
                                                                    
      other nonoperating expense
                                                                    
      net income resulting from early retirement and refinancing of debt
                                                                    
      income from discontinued operations, including gain on sale - net of tax
                                            79,404,000                        
      less: net income attributable to noncontrolling interest
                                                    -273,000                
      net income attributable to arch coal, inc.
                                            -128,363,000 -72,206,000 -70,049,000 45,751,000 -435,489,000 1,206,000 19,056,000 11,079,000 55,601,000 47,819,000 46,678,000  -1,796,000 1,531,000 25,185,000 -15,126,000 30,579,000        
      earnings per common share
                                                                    
      weighted-average shares outstanding
                                                                    
      basic
                                            212,111,000 212,082,000 212,062,000 212,053,000 212,048,000 211,687,000                   
      diluted
                                            212,111,000 212,082,000 212,062,000 212,076,000 212,048,000 211,908,000                   
      costs, expenses and other
                                                                    
      interest expense, net:
                                                                    
      loss per common share
                                                                    
      basic loss per common share
                                             -380                       
      diluted loss per common share
                                             -380                       
      mine closure and asset impairment costs
                                                525,762,000                    
      acquisition and transition costs - icg
                                                                    
      bridge financing costs related to icg
                                                                    
      acquisition and transition costs related to icg
                                                  4,694,000 48,666,000                 
      gain on knight hawk transaction
                                                       -41,577,000             
      other non-operating expense:
                                                                    
      coal sales
                                                   985,087,000 872,938,000 835,394,000 874,705,000 764,295,000 711,874,000 725,472,000 614,957,000 554,612,000 681,040,000 729,881,000 769,458,000 785,117,000 699,350,000 644,399,000 599,151,000 598,745,000 
      cost of coal sales
                                                   709,953,000 653,684,000 622,348,000 651,853,000 570,861,000 550,750,000 566,778,000 489,290,000 467,521,000 547,126,000 533,663,000 567,372,000 568,483,000 514,404,000 480,097,000 476,434,000 482,424,000 
      net income resulting from early retirement of icg debt
                                                                    
      costs related to acquisition of jacobs ranch
                                                         6,560,000 791,000 3,025,000 3,350,000        
      loss on early extinguishment of debt
                                                      -6,776,000              
      less: net (income) loss attributable to noncontrolling interest
                                                     -81,250 -181,000 -118,000 -26,000 2,750 -31,000 35,000 7,000        
      net income attributable to arch coal, inc
                                                       66,156,000             
      non-operating expense
                                                                    
      expenses resulting from early debt extinguishment and termination of hedge accounting for interest rate swaps
                                                                  -370,000 -775,000 
      other non-operating expense
                                                                 -147,000 -436,000  
      preferred stock dividends
                                                                 -53,000 -53,000 -69,000 
      net income available to common stockholders
                                                                 81,320,000 27,227,000 37,483,000 
      other non-operating income:
                                                                    
      other non-operating income
                                                                   357,000 
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2024-09-30 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 2018-09-30 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 2015-03-31 2014-06-30 2014-03-31 2013-03-31 2012-09-30 2012-06-30 2012-03-31 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 2008-09-30 2008-06-30 2008-03-31 2007-12-31 2007-09-30 2007-06-30 
                                                                 
        assets
                                                                 
        current assets
                                                                 
        cash and cash equivalents
      219,595,000 243,707,000 285,531,000 287,807,000 183,097,000 201,492,000 189,739,000 236,059,000 490,321,000 281,944,000 318,725,000 325,194,000 189,707,000 153,516,000 169,593,000 187,492,000 156,655,000 150,022,000 105,157,000 153,020,000 175,428,000 232,429,000 218,750,000 245,679,000 241,590,000 288,332,000 273,387,000 298,337,000 333,548,000 347,580,000 305,372,000 400,205,000 269,814,000 450,781,000 494,788,000 689,972,000 740,154,000 865,761,000 730,119,000 550,756,000 512,527,000 117,770,000 158,509,000 82,345,000 69,220,000 93,593,000 63,753,000 56,966,000 50,374,000 61,138,000 840,293,000 50,560,000 27,766,000 41,066,000 1,161,000 13,234,000 5,080,000 3,389,000 1,693,000 
        short-term investments
      36,347,000 35,583,000 34,252,000 32,724,000 30,447,000 33,607,000 32,116,000 36,993,000 10,671,000   14,463,000 20,084,000 33,256,000 67,483,000 96,765,000 63,128,000 67,237,000  135,667,000                                        
        restricted cash
      1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,100,000 1,101,000 1,101,000 7,104,000 18,962,000 5,953,000 13,919,000         2,926,000   41,755,000 68,984,000 71,050,000 81,563,000 102,236,000 97,542,000 50,409,000    2,290,000 3,450,000 5,740,000 8,866,000 21,428,000 350,966,000                
        trade accounts receivable
      239,994,000 241,910,000 224,084,000 273,522,000 289,994,000 250,479,000 295,157,000 236,999,000 210,349,000 457,883,000 323,167,000 324,304,000 226,206,000 160,154,000 129,086,000 110,869,000 127,292,000 118,835,000 149,225,000 168,125,000 206,149,000 182,824,000 195,095,000 183,318,000 198,362,000 208,100,000 172,604,000 207,059,000 190,256,000 150,399,000 184,483,000 165,522,000  117,405,000 217,667,000 198,314,000 203,782,000 230,002,000 263,294,000 277,634,000 327,402,000 295,012,000 342,721,000 335,052,000 258,499,000 208,060,000 249,189,000 243,567,000 238,770,000 190,738,000 173,994,000 172,085,000 224,964,000 260,564,000 255,003,000 242,186,000 229,965,000 197,005,000 210,110,000 
        other receivables
      8,580,000 6,005,000 10,519,000 13,700,000 16,439,000 18,440,000 18,560,000 18,301,000 13,592,000 12,847,000 9,807,000 8,271,000 3,573,000 3,336,000 3,764,000 3,053,000 2,880,000 2,960,000 19,016,000 21,143,000 24,291,000 32,950,000 44,528,000 26,972,000 12,612,000 11,405,000 29,771,000 23,473,000 21,504,000 22,482,000 19,877,000 17,227,000 15,377,000 18,362,000 21,742,000 15,435,000 35,369,000 44,810,000 81,750,000 71,114,000 70,103,000 66,702,000 83,579,000 91,064,000 44,818,000 44,260,000 45,590,000 33,221,000 31,178,000 40,632,000 20,662,000 31,105,000 42,481,000 24,963,000 17,946,000 16,495,000 19,724,000 19,060,000 22,022,000 
        inventories
      235,091,000 249,865,000 243,690,000 244,261,000 233,213,000 263,310,000 271,155,000 223,015,000 215,172,000 212,752,000 203,997,000 156,734,000 155,870,000 162,531,000 154,395,000 126,008,000 143,396,000 154,690,000 149,986,000 130,898,000 171,543,000 172,841,000 145,607,000 163,878,000 157,205,000 143,831,000 128,960,000 122,436,000 137,056,000 125,194,000 113,462,000 159,410,000 172,698,000 196,720,000 239,035,000 240,113,000 228,726,000 224,806,000 368,240,000 391,526,000 455,091,000 488,686,000 346,331,000 350,201,000 247,908,000 235,616,000 218,958,000 238,317,000 243,158,000 240,776,000 237,293,000 240,828,000 205,770,000 173,862,000 177,285,000 196,166,000 177,785,000 145,222,000 145,045,000 
        other current assets
      47,716,000 52,621,000 63,393,000 64,653,000 51,854,000 49,547,000 55,089,000 71,384,000 49,869,000 54,805,000 50,217,000 52,804,000 52,098,000 35,149,000 39,917,000 58,000,000 55,712,000 70,758,000 87,096,000 97,894,000 113,502,000 56,993,000 64,192,000 95,040,000 86,642,000 68,459,000 70,426,000 63,685,000 61,474,000 74,063,000 93,763,000 36,960,000 39,741,000 104,723,000 51,398,000 59,605,000 54,270,000 55,296,000                      
        total current assets
      788,423,000 830,791,000 862,569,000 917,767,000 806,144,000 817,975,000 862,916,000 823,851,000 991,074,000 1,021,331,000 907,013,000 882,871,000 648,639,000 555,046,000 583,200,000 588,140,000 562,982,000 564,502,000 639,537,000 706,747,000 866,969,000 840,693,000 832,836,000 877,417,000 857,305,000 867,705,000 830,994,000 869,619,000 945,415,000 911,207,000 878,622,000 979,323,000 944,198,000 1,203,782,000 1,319,319,000 1,530,989,000 1,581,788,000 1,737,328,000 1,884,382,000 1,579,686,000 1,568,527,000 1,179,119,000 1,107,583,000 1,388,665,000 798,942,000 734,914,000 763,424,000 745,141,000 730,412,000 686,782,000 1,401,043,000 605,901,000 647,297,000 771,665,000 774,502,000 617,073,000 521,145,000 452,548,000 457,090,000 
        property, plant and equipment
      1,238,534,000 1,244,597,000 1,235,775,000 1,228,891,000 1,200,109,000 1,192,681,000 1,182,351,000 1,187,028,000 1,116,550,000 1,108,926,000 1,111,359,000 1,120,043,000 1,135,399,000 1,102,570,000 1,058,942,000 1,007,303,000 964,472,000 1,066,614,000 1,035,776,000 984,509,000 889,295,000 870,889,000 848,749,000 919,613,000 925,559,000 935,511,000 955,948,000 980,801,000 1,007,570,000 1,027,288,000 1,053,603,000 3,434,941,000 3,493,553,000 3,619,029,000 4,173,038,000 6,371,335,000 6,603,458,000 6,616,144,000 7,272,541,000 7,372,063,000 7,397,131,000 7,892,733,000 7,703,280,000 7,726,456,000 3,263,555,000 3,308,892,000 3,303,028,000 3,346,294,000 3,306,175,000 3,366,186,000 2,745,469,000 2,783,686,000 2,797,697,000 2,655,884,000 2,650,529,000 2,634,351,000 2,463,638,000 2,467,072,000 2,432,573,000 
        other assets
                                                                 
        deferred income taxes
      126,608,000 119,310,000 120,792,000 124,024,000 146,324,000 160,927,000 174,561,000 209,470,000            82,000       22,520,000        20,454,000 50,414,000 48,786,000 48,869,000 67,337,000 65,395,000 65,531,000 65,531,000 15,795,000 7,015,000 18,673,000 361,556,000 33,850,000 20,937,000 3,265,000  33,830,000 23,872,000 32,121,000 89,164,000 71,972,000 35,134,000 18,789,000 40,273,000 32,014,000 
        equity investments
      23,088,000 22,861,000 24,053,000 22,815,000 21,273,000 22,348,000 19,142,000 17,267,000 17,044,000 16,786,000 16,494,000 15,403,000 80,016,000 74,974,000 74,503,000 71,783,000 70,275,000 106,125,000 106,535,000 105,588,000 107,543,000 106,072,000 105,419,000 105,325,000 104,189,000 104,786,000 106,107,000 106,179,000 104,015,000 104,144,000 96,074,000 164,232,000 163,772,000 201,877,000 206,347,000 225,030,000 229,514,000 223,235,000 246,807,000 237,645,000 235,299,000 230,519,000 224,684,000 207,646,000 204,424,000 177,451,000 148,893,000 150,136,000 99,924,000 87,268,000 90,306,000 88,864,000 89,207,000 86,866,000 86,530,000 82,929,000 82,950,000 83,435,000 83,266,000 
        fund for asset retirement obligations
                                                                 
        other noncurrent assets
      46,293,000 46,999,000 47,351,000 48,410,000 51,595,000 54,313,000 56,555,000 59,499,000 65,194,000 66,604,000 76,019,000 78,843,000 66,895,000 62,356,000 57,513,000 55,246,000 55,608,000 65,148,000 75,658,000 69,230,000 70,793,000 71,876,000 76,197,000 95,267,000 62,360,000 68,676,000 59,783,000 65,934,000 75,058,000 102,277,000 108,298,000 58,569,000 62,705,000 58,379,000 119,426,000 123,964,000 153,854,000 158,925,000                      
        total other assets
      343,921,000 335,180,000 336,342,000 337,515,000 359,605,000 376,245,000 387,392,000 422,229,000 212,238,000 183,390,000 132,513,000 114,246,000 146,911,000 137,330,000 132,016,000 127,029,000 125,883,000 171,273,000 182,193,000 176,500,000 178,336,000 177,948,000 181,616,000 200,592,000 166,549,000 173,462,000 192,690,000 172,113,000 179,073,000 206,421,000 204,372,000 243,798,000 247,474,000 283,927,000 355,640,000 412,616,000 470,862,000 469,712,000 763,221,000 984,105,000 988,280,000 1,093,266,000 1,044,398,000 1,036,324,000 837,481,000 836,963,000 768,334,000 799,105,000 776,699,000 787,628,000 647,426,000 639,410,000 644,755,000 514,018,000 523,643,000 598,915,000 609,816,000 564,409,000 584,286,000 
        total assets
      2,370,878,000 2,410,568,000 2,434,686,000 2,484,173,000 2,365,858,000 2,386,901,000 2,432,659,000 2,433,108,000 2,319,862,000 2,313,647,000 2,150,885,000 2,117,160,000 1,930,949,000 1,794,946,000 1,774,158,000 1,722,472,000 1,653,337,000 1,802,389,000 1,857,506,000 1,867,756,000 1,934,600,000 1,889,530,000 1,863,201,000 1,997,622,000 1,949,413,000 1,976,678,000 1,979,632,000 2,022,533,000 2,132,058,000 2,144,916,000 2,136,597,000 4,658,062,000 4,685,225,000 5,106,738,000 5,847,997,000 8,314,940,000 8,656,108,000 8,823,184,000 9,920,144,000 9,935,854,000 9,953,938,000 10,165,118,000 9,855,261,000 10,151,445,000 4,899,978,000 4,880,769,000 4,834,786,000 4,890,540,000 4,813,286,000 4,840,596,000 4,793,938,000 4,028,997,000 4,089,749,000 3,941,567,000 3,948,674,000 3,850,339,000 3,594,599,000 3,484,029,000 3,473,949,000 
        ​
         2,011,535,000    1,849,542,000    1,653,399,000    1,428,982,000                                            
        liabilities and stockholders' equity
                                                                 
        current liabilities
                                                                 
        accounts payable
      153,189,000 186,549,000 178,119,000 205,001,000 198,374,000 188,494,000 176,953,000 211,848,000 186,322,000 165,143,000 147,284,000 131,986,000 102,025,000 116,042,000 122,916,000 103,743,000 99,110,000 104,464,000 108,972,000 133,060,000 166,129,000 138,735,000 138,935,000 119,629,000 131,027,000 127,149,000 134,137,000 137,664,000 127,059,000 103,130,000 95,953,000 89,966,000 78,043,000 128,131,000 152,229,000 167,480,000 160,209,000 160,361,000 229,269,000 304,442,000 316,669,000 294,341,000 293,446,000 286,437,000 183,866,000 198,216,000 172,281,000 157,965,000 149,243,000 128,402,000 129,048,000 140,739,000 165,955,000 200,891,000 174,005,000 168,680,000 150,026,000 152,965,000 163,506,000 
        accrued expenses and other current liabilities
      112,767,000 111,062,000 113,360,000 127,617,000 135,163,000 121,043,000 120,180,000 157,043,000 160,247,000 191,125,000 179,200,000 167,304,000 198,268,000 166,287,000 150,167,000 155,256,000 141,021,000 143,304,000 143,054,000 157,167,000 161,939,000 162,741,000 143,586,000 203,667,000 194,730,000 158,882,000 184,161,000 164,939,000 169,533,000 172,898,000 205,240,000 223,780,000 153,028,000 329,450,000 310,747,000 321,503,000 294,317,000 328,561,000 352,040,000 355,448,000 360,793,000 357,386,000 379,707,000 395,020,000 228,165,000 245,411,000 200,868,000 226,365,000 196,177,000 227,716,000 166,448,000 187,068,000 201,689,000       
        current maturities of debt
      126,897,000 29,721,000 35,341,000 35,343,000 21,926,000 26,414,000 37,405,000 57,988,000 52,179,000 55,920,000 182,611,000 223,050,000 138,587,000 133,812,000 24,597,000 31,097,000 25,987,000 25,702,000 28,456,000 20,753,000 11,925,000 13,068,000 15,210,000 11,478,000 12,533,000 14,328,000 15,783,000 8,566,000 7,414,000 7,898,000 11,038,000 3,398,000  5,107,210,000 32,237,000 34,368,000 27,266,000 29,950,000 28,306,000                     
        total current liabilities
      392,853,000 327,332,000 326,820,000 367,961,000 355,463,000 335,951,000 334,538,000 426,879,000 398,748,000 412,188,000 509,095,000 522,340,000 438,880,000 416,141,000 297,680,000 290,096,000 266,118,000 273,470,000 280,482,000 310,980,000 339,993,000 314,544,000 297,731,000 334,774,000 338,290,000 300,359,000 334,081,000 311,169,000 304,006,000 283,926,000 312,231,000 317,144,000 231,071,000 5,564,791,000 495,213,000 523,351,000 481,792,000 518,872,000 610,258,000 779,083,000 795,812,000 763,183,000 726,133,000 1,115,858,000 485,727,000 527,346,000 518,204,000 635,560,000 591,638,000 631,727,000 496,469,000 530,365,000 582,855,000 791,068,000 819,947,000 745,276,000 556,515,000 482,710,000 419,505,000 
        long-term debt
       101,661,000 107,959,000 105,252,000 107,515,000 109,216,000 110,899,000 116,288,000 121,914,000 127,107,000 132,290,000 337,623,000 416,446,000 402,076,000 519,357,000 477,215,000 368,278,000 323,854,000 330,036,000 290,066,000 292,781,000 295,263,000 297,733,000 302,830,000 305,157,000 307,742,000 310,134,000 312,604,000 315,639,000 318,030,000 351,841,000 30,037,000  30,953,000 5,108,492,000 5,117,982,000 5,116,353,000 5,112,995,000 5,082,205,000 4,465,445,000 4,464,351,000 3,967,796,000 3,841,330,000 3,773,923,000 1,539,028,000 1,538,744,000 1,538,470,000 1,540,363,000 1,540,289,000 1,540,223,000 1,692,167,000 1,240,793,000 1,238,807,000 956,490,000 958,383,000 1,058,696,000 1,085,579,000 1,135,752,000 1,226,224,000 
        asset retirement obligations
      267,486,000 263,098,000 260,252,000 255,740,000 234,386,000 234,842,000 237,142,000 235,736,000 195,655,000 194,249,000 193,745,000 192,672,000 210,843,000 213,387,000 224,615,000 230,732,000 239,614,000 238,883,000 239,969,000 242,432,000 238,440,000 236,317,000 233,614,000 319,601,000 316,341,000 312,544,000 308,855,000 334,479,000 342,680,000 339,865,000 337,227,000 394,699,000 390,634,000 396,659,000 414,194,000 404,844,000 395,813,000 390,408,000 410,975,000 426,044,000 424,289,000 432,620,000 415,877,000 412,324,000 336,975,000 334,257,000 323,025,000 317,257,000 311,130,000 305,094,000 270,642,000 265,904,000 260,876,000 231,352,000 227,609,000 223,648,000 219,991,000 211,568,000 207,920,000 
        accrued pension benefits
      816,000 832,000 861,000 878,000 1,057,000 1,076,000 1,089,000 1,101,000 493,000 591,000 948,000 1,300,000 1,527,000 2,274,000 2,088,000 2,879,000 6,108,000 13,875,000 18,897,000 5,476,000 12,491,000 11,649,000 15,452,000 5,101,000 7,481,000 13,370,000 14,036,000 17,884,000 32,092,000 37,510,000 38,884,000 23,716,000 19,853,000 27,373,000 12,061,000 14,436,000 13,925,000 10,484,000 69,342,000 45,160,000 49,040,000 49,378,000 16,235,000 36,047,000 38,808,000 49,154,000 64,145,000 67,252,000 69,277,000 68,266,000 63,904,000 75,976,000 76,023,000       
        accrued postretirement benefits other than pension
      46,530,000 46,800,000 47,384,000 47,494,000 50,360,000 50,802,000 51,770,000 49,674,000 72,890,000 74,300,000 73,828,000 73,565,000 93,317,000 95,491,000 95,936,000 94,388,000 85,642,000 86,772,000 80,069,000 80,567,000 78,308,000 79,992,000 81,296,000 105,400,000 106,934,000 104,902,000 102,369,000 104,733,000 101,407,000 101,786,000 101,445,000 87,123,000 87,286,000 99,810,000 33,966,000 34,453,000 38,034,000 37,995,000 46,413,000 41,061,000 42,028,000 42,784,000 88,820,000 87,626,000 36,920,000 37,793,000 45,609,000 45,441,000 45,095,000 43,865,000 40,566,000 60,250,000 58,943,000 62,227,000 61,204,000 60,354,000 59,181,000 53,155,000 52,255,000 
        accrued workers’ compensation
      158,902,000 157,663,000 155,838,000 154,650,000 144,714,000 152,942,000 153,870,000 155,756,000 222,648,000 222,289,000 222,462,000 224,105,000 249,594,000 249,256,000 249,133,000 244,695,000 219,851,000 219,095,000 218,626,000 215,599,000 174,118,000 173,621,000 168,851,000 180,880,000 185,068,000 185,159,000 184,835,000 192,262,000 186,128,000 184,792,000 184,568,000 119,828,000 118,997,000 112,270,000 95,905,000 98,683,000 74,083,000 75,817,000 81,039,000 85,251,000 82,372,000 74,012,000 64,421,000 65,027,000 35,964,000 35,290,000 28,226,000 27,676,000 27,990,000 29,110,000 27,706,000 26,527,000 28,728,000 39,467,000 40,561,000 40,712,000 41,071,000 45,679,000 44,667,000 
        other noncurrent liabilities
      60,337,000 62,617,000 68,124,000 72,742,000 76,213,000 76,508,000 79,357,000 82,094,000 121,453,000 94,215,000 94,265,000 81,689,000 105,699,000 97,792,000 103,906,000 98,906,000 102,080,000 98,658,000 95,663,000 82,100,000 93,033,000 80,194,000 68,577,000 61,896,000 49,194,000 64,140,000 59,457,000 76,923,000 65,048,000 77,301,000 63,824,000 65,824,000 33,918,000 119,171,000 248,800,000 141,804,000 172,512,000 181,866,000 227,363,000 182,464,000 223,131,000 268,585,000 277,490,000 258,261,000 124,243,000 110,234,000 120,058,000 95,559,000 113,735,000 98,243,000 80,473,000 69,724,000 80,409,000 111,206,000 113,096,000 109,063,000 100,576,000 113,062,000 100,655,000 
        total liabilities
      926,924,000 960,003,000 967,238,000 1,004,717,000 969,708,000 961,337,000 968,665,000 1,067,528,000 1,133,801,000 1,124,939,000 1,226,633,000 1,433,294,000 1,516,306,000 1,476,417,000 1,492,715,000 1,438,911,000 1,287,691,000 1,254,607,000 1,263,742,000 1,227,220,000 1,229,164,000 1,191,580,000 1,163,254,000 1,310,482,000 1,308,465,000 1,288,216,000 1,313,767,000 1,350,054,000 1,347,000,000 1,343,210,000 1,390,020,000 6,334,156,000 6,312,215,000 6,351,027,000 6,453,437,000 6,754,617,000 6,624,719,000 6,696,494,000 7,137,790,000 6,770,587,000 6,811,518,000 6,580,954,000 6,310,793,000 6,613,036,000 2,597,665,000 2,632,818,000 2,637,737,000 2,729,108,000 2,699,154,000 2,716,528,000 2,671,927,000 2,269,539,000 2,326,641,000 2,191,810,000 2,220,800,000 2,237,749,000 2,062,913,000 2,041,926,000 2,051,226,000 
        stockholders' equity
                                                                 
        common stock, 0.01 par value...
      308,000 308,000 308,000 306,000 305,000 301,000 301,000 288,000 286,000 286,000 256,000 255,000 254,000 254,000 254,000 253,000 252,000 252,000 252,000 252,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000 250,000  2,145,000 2,145,000 2,145,000 2,145,000 2,145,000 2,141,000 2,141,000 2,141,000 2,141,000 2,138,000  2,135,000 2,127,000 1,647,000 1,645,000 1,643,000 1,643,000 1,643,000 1,643,000 1,643,000 1,448,000 1,448,000 1,447,000 1,447,000 1,444,000 1,436,000   
        paid-in capital
      764,202,000 758,880,000 754,054,000 720,029,000 716,956,000 710,118,000 703,712,000 724,660,000 766,427,000 774,144,000 748,999,000 784,356,000 779,013,000 774,665,000 770,052,000 767,484,000 744,112,000 739,156,000 734,315,000 730,551,000 734,829,000 728,996,000 723,143,000 712,295,000 708,127,000 703,980,000 700,125,000 697,324,000 694,780,000 692,253,000 688,424,000 3,056,307,000 3,055,646,000 3,054,211,000 3,052,910,000 3,050,216,000 3,044,082,000 3,040,946,000 3,029,536,000 3,024,435,000 3,022,014,000 3,024,553,000 3,012,628,000 2,991,550,000 1,740,765,000 1,734,709,000 1,731,209,000 1,728,806,000 1,724,999,000 1,721,230,000 1,718,088,000 1,388,454,000 1,385,073,000 1,378,633,000 1,371,856,000 1,364,462,000 1,358,695,000 1,351,103,000 1,349,527,000 
        retained earnings
      1,839,125,000 1,849,622,000 1,854,621,000 1,830,018,000 1,737,468,000 1,737,661,000 1,705,988,000 1,565,374,000 1,299,024,000 1,234,979,000 986,797,000 712,478,000 489,914,000 400,771,000 372,882,000 378,906,000 457,432,000 648,909,000 698,292,000 731,425,000 746,928,000 647,440,000 592,296,000 449,122,000 333,753,000 298,664,000 247,232,000 173,676,000 113,574,000 85,117,000 33,449,000         197,749,000 158,374,000 600,230,000 586,067,000 593,896,000 600,751,000 561,418,000 529,852,000 499,423,000 449,515,000 465,934,000 479,025,000 468,462,000 496,451,000 429,254,000 344,401,000 244,383,000 173,186,000 102,033,000 84,798,000 
        treasury stock
      -1,193,884,000 -1,193,876,000 -1,178,735,000 -1,109,679,000 -1,107,878,000 -1,079,396,000 -1,005,165,000 -986,171,000 -884,879,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -827,381,000 -816,882,000 -725,524,000 -662,132,000 -495,232,000 -418,985,000 -340,698,000 -302,109,000 -217,728,000 -51,043,000   -53,863,000 -53,863,000            -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000 -53,848,000      
        accumulated other comprehensive income
      34,203,000 35,631,000 37,200,000 38,782,000 49,299,000 56,880,000 59,158,000 61,429,000 5,203,000 6,680,000 15,581,000 14,158,000    -35,701,000 -8,769,000 -13,154,000 -11,714,000 5,689,000 40,311,000 46,788,000 46,390,000 20,705,000 17,803,000 26,266,000 20,367,000 18,957,000 27,497,000 24,086,000 24,454,000    5,967,000 6,845,000 33,485,000 35,062,000       2,280,000          10,170,000 2,301,000    
        total stockholders’ equity
      1,443,954,000 1,450,565,000 1,467,448,000 1,479,456,000 1,396,150,000 1,425,564,000 1,463,994,000 1,365,580,000 1,186,061,000 1,188,708,000 924,252,000 683,866,000 414,643,000 318,529,000 281,443,000 283,561,000 365,646,000 547,782,000 593,764,000 640,536,000 705,436,000 697,950,000 699,947,000 687,140,000 640,948,000 688,462,000 665,865,000 672,479,000 785,058,000 801,706,000 746,577,000     1,560,323,000 2,031,389,000 2,126,690,000 2,782,354,000 3,165,267,000 3,124,920,000 3,572,425,000 3,533,207,000 3,527,377,000 2,291,595,000 2,237,507,000 2,186,876,000 2,151,439,000 2,105,142,000 2,115,106,000 2,113,071,000 1,750,614,000  1,749,757,000 1,727,874,000 1,612,590,000 1,531,686,000 1,442,103,000 1,422,723,000 
        total liabilities and stockholders’ equity
      2,370,878,000 2,410,568,000 2,434,686,000 2,484,173,000 2,365,858,000 2,386,901,000 2,432,659,000 2,433,108,000 2,319,862,000 2,313,647,000 2,150,885,000 2,117,160,000 1,930,949,000 1,794,946,000 1,774,158,000 1,722,472,000 1,653,337,000 1,802,389,000 1,857,506,000 1,867,756,000 1,934,600,000 1,889,530,000 1,863,201,000 1,997,622,000 1,949,413,000 1,976,678,000 1,979,632,000 2,022,533,000 2,132,058,000 2,144,916,000 2,136,597,000   5,106,738,000  8,314,940,000 8,656,108,000 8,823,184,000 9,920,144,000 9,935,854,000 9,953,938,000 10,165,118,000 9,855,261,000 10,151,445,000 4,899,978,000 4,880,769,000 4,834,786,000 4,890,540,000 4,813,286,000 4,840,596,000 4,793,938,000 4,028,997,000  3,941,567,000 3,948,674,000 3,850,339,000 3,594,599,000 3,484,029,000 3,473,949,000 
        coal lands and mineral rights
         402,387,000    406,085,000    406,822,000    406,095,000    450,539,000       390,920,000    387,591,000   3,713,639,000            2,523,172,000    2,417,151,000       1,690,176,000   
        plant and equipment
         1,099,511,000    968,420,000    844,107,000    734,194,000    639,399,000       445,407,000    418,182,000   2,359,674,000            2,397,444,000    2,261,929,000       1,729,501,000   
        deferred mine development
         509,637,000    475,037,000    402,470,000    288,693,000    252,108,000       267,063,000    280,323,000   553,286,000            872,329,000    832,976,000       672,496,000   
        less accumulated depreciation, depletion and amortization
         -782,644,000    -662,514,000    -533,356,000    -421,679,000    -357,537,000       -147,442,000    -32,493,000               -2,484,053,000    -2,145,870,000       -1,628,535,000   
        accumulated other comprehensive loss
                  -27,157,000 -29,780,000 -34,364,000                 -1,706,000 -3,362,000             -6,417,000 -21,980,000 -24,585,000 -17,167,000 -19,853,000 -31,837,000 -53,902,000 -74,894,000 -5,729,000   -1,632,000 -12,466,000 -13,034,000 
        short term investments
                        129,057,000  176,056,000 162,656,000 164,664,000 162,530,000 160,894,000 144,652,000 155,846,000 154,629,000 159,822,000 122,505,000 88,072,000 111,451,000 203,417,000 200,192,000 199,731,000 249,518,000 248,647,000 248,572,000 248,414,000 99,359,000                    
        prepaid royalties
                         1,600,000       4,280,000    2,281,000 4,805,000 7,737,000 10,022,000 10,352,000 12,841,000 7,932,000 6,896,000 13,105,000 12,120,000 11,214,000 18,025,000 29,163,000 38,119,000 42,719,000 33,932,000 45,129,000 49,441,000 42,090,000 21,085,000 25,711,000 23,582,000 35,401,000 52,662,000 50,311,000 24,113,000 22,055,000 15,868,000 13,521,000 
        coal derivative assets
                                    262,000 2,180,000 4,091,000 8,035,000 13,743,000 14,777,000 14,122,000 12,316,000 20,856,000 40,837,000 53,351,000 22,043,000 2,595,000 12,780,000 15,952,000 15,191,000 10,322,000 14,598,000 14,801,000 18,807,000 23,721,000 23,408,000 25,335,000 86,545,000 140,977,000 45,393,000    
        successor common stock, 0.01 par value...
                                    250,000                             
        predecessor common stock, 0.01 par value...
                                                                 
        liabilities and stockholders' deficit
                                                                 
        liabilities not subject to compromise
                                                                 
        total liabilities not subject to compromise
                                     1,038,371,000 881,759,000                           
        liabilities subject to compromise
                                     5,295,785,000 5,430,456,000                           
        stockholders' deficit
                                                                 
        accumulated deficit
                                     -4,678,977,000 -4,627,556,000                           
        total stockholders’ deficit
                                     -1,676,094,000 -1,626,990,000                           
        total liabilities and stockholders’ deficit
                                     4,658,062,000 4,685,225,000  5,847,997,000                         
        trade accounts receivable (net of allowance for doubtful accounts of 7.8 million for both periods, respectively.
                                      129,087,000                           
        liabilities and stockholders’ equity
                                                                 
        stockholders’ equity
                                                                 
        liabilities and stockholders’ deficit
                                                                 
        stockholders’ deficit
                                                                 
        other
                                            88,977,000 67,495,000 67,568,000 96,484,000 107,462,000 121,123,000 101,153,000 104,262,000 96,633,000 88,094,000 106,776,000 113,606,000 45,539,000 40,461,000 53,459,000 42,839,000 59,847,000 44,352,000 47,747,000 31,731,000 32,685,000 
        other assets:
                                                                 
        goodwill
                                            265,423,000 480,312,000 480,312,000 596,103,000 539,963,000 539,963,000 114,963,000 114,963,000 113,701,000 113,701,000 113,701,000 113,701,000 46,832,000 46,832,000 46,832,000 46,832,000 40,032,000 40,032,000 40,032,000 40,032,000 40,032,000 
        coal derivative liabilities
                                            643,000 3,498,000 7,090,000 9,100,000 5,824,000 5,791,000 4,178,000 4,947,000 5,721,000 7,570,000 2,820,000 2,244,000 5,640,000 7,036,000 10,044,000 23,544,000 52,410,000 8,053,000    
        current maturities of debt and short-term borrowings
                                             115,695,000 111,260,000 102,356,000 47,156,000 428,610,000 69,518,000 70,997,000 139,334,000 243,660,000 243,398,000 267,464,000 195,333,000 195,522,000 205,167,000 385,566,000 376,248,000 390,387,000 217,614,000   
        redeemable noncontrolling interest
                                              17,500,000 11,739,000 11,261,000 11,032,000 10,718,000 10,444,000 10,173,000 9,993,000 8,990,000 8,962,000 8,940,000 8,844,000        
        common stock
                                               2,141,000                  
        current assets:
                                                                 
        current liabilities:
                                                                 
        stockholders’ equity:
                                                                 
        property, plant and equipment:
                                                                 
        liabilities and equity
                                                                 
        equity:
                                                                 
        total arch coal, inc. stockholders’ equity
                                                          1,754,230,000       
        noncontrolling interest
                                                          8,878,000       
        total equity
                                                          1,763,108,000       
        total liabilities and equity
                                                          4,089,749,000       
        accrued expenses
                                                           181,067,000 217,284,000 178,156,000 188,875,000 169,042,000 196,216,000 
        preferred stock, 0.01 par value...
                                                              1,000   
        current portion of debt and short-term borrowings
                                                               160,703,000  
        preferred stock, .01 par value...
                                                               1,000 1,000 
        common stock, .01 par value...
                                                               1,432,000 1,431,000 
        current portion of debt
                                                                59,783,000 
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2024-09-30 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 2018-03-31 2017-03-31 2013-03-31 2012-06-30 2012-03-31 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 
                                                     
          operating activities
                                                     
          net income
        -6,221,000 14,833,000 55,953,000 114,886,000 73,691,000 77,353,000 198,108,000 470,471,000 181,008,000 407,563,000 271,872,000 226,606,000 89,143,000 27,866,000 -6,042,000 -78,525,000 -191,467,000 -49,324,000 -25,299,000 -8,551,000 106,769,000 62,840,000 72,741,000 59,985,000 51,668,000 -70,049,000 -435,424,000 1,409,000 15,679,000 11,397,000 55,874,000 48,031,000 46,859,000 66,274,000 -1,770,000 1,552,000 25,216,000 -15,161,000 30,572,000 62,338,000 97,848,000 112,997,000 81,147,000 81,373,000 27,280,000 
          adjustments to reconcile to cash from operating activities:
                                                     
          depreciation, depletion and amortization
        40,890,000 38,439,000 38,820,000 38,145,000 36,717,000 36,077,000 35,479,000 34,352,000 33,958,000 32,780,000 32,210,000 35,886,000 30,760,000 27,884,000 25,797,000 27,447,000 32,630,000 30,167,000 31,308,000 29,856,000 30,402,000 26,524,000 25,273,000 29,703,000 31,921,000 118,868,000 132,868,000 139,966,000 123,026,000 95,183,000 83,537,000 95,931,000 92,857,000 87,759,000 88,519,000 88,622,000 71,468,000 68,477,000 73,041,000 75,668,000 72,185,000 71,953,000 73,042,000 67,824,000 58,628,000 
          accretion on asset retirement obligations
        5,869,000 5,870,000 5,869,000 5,293,000 5,292,000 5,293,000 5,292,000 4,431,000 4,430,000 4,430,000 4,430,000 5,437,000 5,437,000 5,437,000 5,437,000 4,948,000 4,947,000 4,986,000 5,006,000 5,137,000 5,137,000 5,137,000 5,137,000 6,992,000 7,623,000                     
          deferred income taxes
        -6,912,000 1,907,000 3,660,000 20,530,000 16,737,000 14,276,000 35,548,000     -3,000 -361,000 372,000 203,000 347,000   -179,000 295,000   12,127,000 5,830,000    2,699,000 21,899,000 -1,026,000 -4,844,000 -2,842,000 -4,869,000 150,000 -19,503,000 -9,414,000 8,689,000 -14,440,000 7,155,000 -2,859,000 11,737,000 -811,000   
          employee stock-based compensation expense
        5,374,000 4,857,000 5,588,000 5,744,000 6,493,000 6,439,000 6,767,000 6,546,000 6,285,000 6,349,000 8,203,000 7,698,000 4,343,000 4,613,000 3,885,000 3,528,000 4,971,000 4,974,000 3,962,000 4,684,000 5,832,000 5,822,000 5,651,000 3,845,000 2,426,000 2,713,000 2,935,000 4,079,000 1,948,000                 
          amortization relating to financing activities
        727,000 783,000 658,000 434,000 433,000 434,000 450,000 501,000 828,000 360,000 770,000 1,748,000 1,691,000 1,784,000 1,326,000 2,410,000 1,243,000 975,000 971,000 934,000 931,000 919,000 907,000 1,080,000 535,000 6,167,000 4,660,000 4,288,000                  
          gain on disposals and divestitures
        -63,000 -126,000 -24,000  -321,000 -114,000 -279,000  -315,000 -345,000 -352,000 24,133,000 -444,000 -225,000 -188,000                               
          reclamation work completed
        -1,587,000 -3,096,000 -1,355,000 -3,814,000 -5,885,000 -7,870,000 -3,887,000 -2,491,000 -3,025,000 -3,926,000 -4,278,000 -2,847,000 -7,982,000                                 
          contribution to fund for asset retirement obligations
                                                     
          changes in:
                                                     
          receivables
        630,000 -13,312,000 52,618,000 18,187,000 -36,893,000 44,911,000 -57,968,000 -31,361,000 246,790,000 -137,756,000 -399,000 -97,092,000 -66,290,000 -30,639,000 -18,929,000 16,241,000 -8,401,000 32,089,000 23,728,000 35,335,000 -22,493,000 10,461,000 7,410,000 -28,728,000 37,134,000  -35,791,000 88,082,000   -53,586,000 41,431,000 -4,661,000 -7,044,000 -37,013,000 -15,991,000 2,803,000 69,987,000 -9,005,000 19,775,000 -8,074,000 -12,820,000 -8,752,000 -33,623,000 16,115,000 
          inventories
        14,773,000 -6,175,000 571,000 -11,047,000 30,096,000 7,845,000 -48,140,000 -7,843,000 -2,420,000 -8,755,000 -47,263,000 -864,000 6,661,000 -8,136,000 -28,387,000 3,373,000 11,293,000 -4,704,000 -19,088,000 30,822,000 1,297,000 -27,233,000 -20,137,000 -14,871,000 -11,732,000      -12,292,000 -16,658,000 19,360,000 4,840,000 -2,382,000 17,207,000 3,535,000 -35,058,000 -14,202,000 -17,706,000 3,423,000 18,881,000 -18,381,000 -32,563,000 -182,000 
          accounts payable, accrued expenses and other current liabilities
        -33,601,000 4,258,000 -33,481,000 -82,000 22,488,000 9,779,000 -63,508,000 26,156,000 21,708,000 22,968,000 14,115,000 32,720,000 -1,763,000 763,000 13,827,000 4,408,000 -7,585,000 -3,688,000 -39,201,000 -29,791,000 -2,928,000 22,358,000 -17,861,000 -26,052,000 -20,529,000 38,249,000   -5,170,000 40,508,000 -31,596,000 66,928,000 -11,181,000 38,904,000 -6,844,000 29,843,000 -22,847,000 -13,869,000 -37,891,000       
          income taxes
        303,000 -75,000 30,000 61,000 -171,000 -2,319,000 1,491,000 -31,333,000 399,000 -15,000 442,000 573,000 -1,090,000 2,370,000 -33,000      7,865,000 24,499,000 76,000 11,596,000 -4,965,000 458,000 -133,000 23,002,000                -38,207,000 4,865,000 
          other
        6,653,000 12,881,000 1,240,000 1,870,000 -15,942,000 3,315,000 19,371,000 -16,519,000 6,984,000 2,698,000 17,356,000 -54,614,000 5,007,000 17,285,000 8,621,000 3,104,000 19,269,000 2,095,000 16,865,000 214,000 13,596,000 -2,861,000 6,197,000 8,005,000 6,964,000 16,307,000  4,102,000 10,949,000 -8,723,000 23,729,000 -33,999,000 17,785,000 -2,637,000 26,071,000 -24,283,000 -114,000 3,606,000 4,827,000 -17,897,000 -10,831,000 10,808,000 8,958,000  23,106,000 
          cash from operating activities
        24,913,000 59,180,000 128,266,000 181,556,000 130,932,000 196,765,000 126,121,000 194,309,000 454,064,000 268,228,000 292,939,000 146,702,000 65,473,000 20,423,000 5,686,000 5,192,000 29,992,000 37,957,000 -12,035,000 85,661,000 108,147,000 140,922,000 84,984,000 66,867,000 125,529,000 43,291,000 40,318,000 54,990,000 157,167,000 228,055,000 86,145,000 240,467,000 197,325,000 166,024,000 93,331,000 136,537,000 86,252,000 103,064,000 57,127,000 171,043,000 172,579,000 201,786,000 133,729,000 66,428,000 95,113,000 
          investing activities
                                                     
          capital expenditures
        -34,522,000 -46,920,000 -45,446,000 -55,007,000 -44,424,000 -46,065,000 -30,541,000 -78,211,000 -41,360,000 -30,869,000 -22,288,000 -33,394,000 -64,089,000 -71,199,000 -76,758,000 -80,160,000 -57,100,000 -60,871,000 -87,690,000 -128,960,000 -49,542,000 -48,707,000 -39,147,000 -9,453,000 -5,950,000 -38,711,000 -93,074,000 -49,625,000 -139,983,000 -31,975,000 -43,117,000 -33,471,000 -54,676,000 -191,886,000 -83,222,000 -78,045,000 -91,589,000 -244,491,000 -64,478,000 -93,541,000 
          free cash flows
        -9,609,000 12,260,000 82,820,000 126,549,000 86,508,000 150,700,000 95,580,000 116,098,000 412,704,000 237,359,000 270,651,000 113,308,000 1,384,000 -50,776,000 -71,072,000 -74,968,000 -27,108,000 -22,914,000 -99,725,000 -43,299,000 58,605,000 92,215,000 45,837,000 57,414,000 119,579,000 43,291,000 40,318,000 54,990,000 157,167,000 228,055,000 47,434,000 147,393,000 147,700,000 26,041,000 61,356,000 93,420,000 52,781,000 48,388,000 -134,759,000 87,821,000 94,534,000 110,197,000 -110,762,000 1,950,000 1,572,000 
          minimum royalty payments
        -938,000 -50,000 -62,000 -1,000,000 -113,000 -69,000   -62,000 -1,062,000 -62,000 -62,000 -62,000 -1,062,000 -62,000 -62,000 -62,000 -1,062,000 -63,000 -62,000 -63,000                     
          proceeds from disposals and divestitures
        20,000 109,000 90,000 2,692,000 924,000 96,000 343,000 9,000 416,000 1,187,000 360,000 20,093,000 697,000 250,000 188,000 151,000 294,000 329,000 233,000 4,336,000 208,000 983,000 608,000 54,000 420,000                     
          purchases of short-term investments
        -10,862,000 -19,203,000 -11,332,000 -12,026,000 -9,614,000 -10,842,000 -2,930,000 -29,056,000        -44,031,000                              
          proceeds from sales of short-term investments
        10,398,000 17,979,000 9,867,000 9,875,000 12,929,000 9,488,000 8,000,000 2,887,000 14,450,000 5,500,000 13,000,000 34,005,000 34,981,000 10,038,000                              
          investments in and advances to affiliates
        -3,814,000 -2,313,000 -4,203,000 -5,135,000 -2,283,000 -5,598,000 -4,329,000 -2,883,000 -2,665,000 -1,939,000 -2,088,000 -580,000 -1,609,000 -1,114,000 -490,000 -320,000 -739,000 -689,000 -1,535,000 -1,079,000 -2,196,000  -7,905,000                     
          cash from investing activities
        -38,780,000 -51,286,000 -51,074,000 -59,663,000 -42,468,000 -53,921,000 -29,570,000 -107,254,000 -54,353,000 -32,621,000 -9,566,000 -8,381,000 -52,063,000 -38,006,000 -42,765,000 -114,064,000 -53,653,000 16,588,000 -74,880,000 -85,109,000 -64,309,000 -47,493,000 -42,200,000 1,481,000 -44,069,000      -93,529,000 -127,343,000 -52,342,000 -144,153,000 -65,291,000 -821,137,000 -34,620,000 -59,966,000 -214,659,000 -93,398,000 -79,519,000 -90,668,000 -263,960,000 -64,770,000 -94,222,000 
          financing activities
                                                     
          proceeds from issuance of term loan due 2025
        20,000,000                                           
          payments on term loan due 2025
        -3,333,000                                             
          payments on term loan due 2024
          -3,502,000 -750,000 -750,000 -750,000 -750,000 -750,000 -750,000        -750,000 -750,000 -750,000  -750,000 -750,000 -750,000 -750,000                      
          payments on convertible debt
           -58,430,000 -58,857,000 -19,332,000                                     
          net payments on other debt
                  -10,134,000 9,013,000 -1,413,000 -9,259,000 -9,536,000 3,425,000 -5,755,000 -8,048,000 -5,544,000 6,704,000 -3,232,000 -4,212,000 -4,633,000 -3,431,000 -2,810,000      -5,161,000  -1,545,000 -3,507,000 -4,742,000 10,290,000 -3,513,000 -4,400,000 -5,363,000  -2,100,000 -4,481,000 -4,414,000   
          debt financing costs
        -16,000 -1,500,000     -345,000    -520,000 -343,000 -1,194,000 -6,190,000 -2,357,000 -749,000 -422,000      -7,228,000      -8,000 -121,000 -12,193,000 -237,000 -200,000 -63,000 -25,022,000 -125,000 -4,449,000 -14,000   -63,000  
          purchases of treasury stock
        -16,998,000 -13,749,000 -3,006,000 -28,699,000 -72,997,000 -20,806,000 -100,292,000            -11,999,000 -89,857,000 -67,393,000 -75,749,000 -38,186,000                -5,916,000      
          dividends paid
        -5,187,000 -20,095,000 -43,662,000 -22,335,000 -71,877,000 -45,011,000 -66,902,000 -191,754,000 -110,071,000 -150,716,000 -3,851,000     -600,000 -7,645,000 -7,956,000 -7,000,000 -7,425,000 -7,839,000 -8,335,000       -16,269,000 -16,252,000 -16,251,000 -16,247,000 -14,623,000 -14,622,000 -14,622,000 -12,863,000 -12,862,000 -12,858,000 -12,993,000 -12,986,000 -10,010,000 -10,220,000 -10,045,000 
          payments for taxes related to net share settlement of equity awards
        -80,000 -24,259,000 -3,010,000 -13,000 -162,000 -27,055,000 -2,144,000 -81,000 -4,827,000 -3,547,000 23,000 -1,316,000 -1,849,000 -15,000 -133,000 -198,000                           
          proceeds from warrants exercised
                                                     
          cash from financing activities
        -10,245,000 -49,718,000 -79,468,000 -17,183,000 -106,859,000 -131,091,000 -142,871,000 -341,317,000 -191,334,000 -272,388,000 -289,843,000 -2,834,000 16,778,000 -10,352,000 32,189,000 131,743,000 44,213,000 -9,680,000 39,052,000 -22,960,000 -100,839,000 -79,750,000 -88,971,000 -50,692,000 -39,252,000  463,555,000 8,381,000 -61,776,000 2,846,320,000 -16,989,000 -83,284,000 -138,196,000 -15,279,000 -38,804,000 -94,555,000 738,101,000 -20,304,000 114,649,000 -48,062,000 -53,155,000 -123,191,000 138,385,000 33,000 805,000 
          decrease in cash and cash equivalents, including restricted cash
        -24,112,000 -41,824,000 -2,276,000   11,753,000 -46,320,000   -36,781,000 -6,470,000   -27,935,000 -4,890,000   44,865,000 -47,863,000 -22,408,000 -57,001,000                         
          cash and cash equivalents, including restricted cash, beginning of period
        288,907,000 237,159,000 326,295,000 193,445,000 153,020,000 264,937,000 273,602,000                      
          cash and cash equivalents, including restricted cash, end of period
        -24,112,000 -41,824,000 286,631,000 104,710,000 -18,395,000 11,753,000 190,839,000 -254,262,000 208,377,000 -36,781,000 319,825,000 135,487,000 30,188,000 -27,935,000 188,555,000 22,871,000 20,552,000 44,865,000 105,157,000 -22,408,000 -57,001,000 13,679,000 218,750,000 291,258,000                      
          supplemental cash flow information
                                                     
          cash and cash equivalents
        -24,112,000 -41,824,000 285,531,000 104,710,000 -18,395,000 11,753,000 189,739,000 -254,262,000 208,377,000 -36,781,000 318,725,000  36,191,000 -16,077,000 169,593,000  6,633,000 44,865,000 105,157,000  -57,001,000 13,679,000 218,750,000 288,332,000                      
          restricted cash
                               2,926,000                      
          ​
          286,631,000  -18,395,000 11,753,000 190,839,000  208,377,000 -36,781,000 319,825,000  30,188,000 -27,935,000 188,555,000  20,552,000 44,865,000 105,157,000                           
          (gain) loss on disposals and divestitures
                                                     
          coal derivative assets and liabilities, including margin account
           211,000 -46,000 2,869,000 -1,462,000 -3,870,000 -12,566,000 1,877,000 15,833,000                                   
          asset retirement obligations
                                                     
          pension, postretirement and other postemployment benefits
                                                     
          proceeds from equipment financing
                                                     
          proceeds from tax exempt bonds
                                                     
          increase in cash and cash equivalents, including restricted cash
           104,710,000    -254,262,000    135,487,000    22,871,000       -46,187,000 17,656,000                      
          cash paid during the period for interest
                                                     
          gain on property insurance recovery related to mountain laurel longwall
                       -14,518,000 -9,000,000                           
          non-cash asset impairment and restructuring
                                                     
          proceeds from property insurance recovery related to mountain laurel longwall
                                                     
          purchase of capped call related to convertible debt
                                                     
          cash refunded during the period for income taxes
                                                     
          contribution to fund asset retirement obligations
                                                     
          payments on term loan
                  -271,537,000 -5,645,000 -750,000 -750,000 -750,000                               
          preference rights lease application settlement income
                                                    
          proceeds from convertible debt
                                                     
          gains on disposals and divestitures
                        -280,000 -2,966,000 -214,000     134,000 -347,000                     
          asset impairment
                                                     
          purchases of short term investments
                         -511,000 -17,196,000 -46,638,000 -69,124,000 -61,552,000 -27,902,000 -38,458,000 -78,523,000                     
          proceeds from sales of short term investments
                         62,858,000 23,221,000 86,904,000 55,746,000 63,924,000 26,500,000 49,400,000 45,886,000 11,534,000                    
          adjustments to reconcile net income to cash from operating activities:
                                                     
          amortization of sales contracts
                           -357,000 -153,000 11,000 65,000 3,051,000 14,690,000                     
          prepaid royalties expensed
                                2,281,000 3,537,000 7,965,000 8,586,000 7,389,000 10,575,000 8,916,000 8,415,000 10,142,000 9,449,000 6,599,000 5,606,000 6,967,000 7,712,000 9,461,000 9,066,000 10,617,000 7,681,000 8,863,000 3,510,000 1,070,000 
          net income resulting from early retirement of debt and debt restructuring
                                2,030,000                     
          income taxes receivable/payable
                                                     
          proceeds from issuance of term loan due 2024
                                298,500,000                     
          payments to extinguish term loan due 2021
                                -325,684,000                     
          expenses related to debt restructuring
                                                     
          (gains) losses on disposals and divestitures
                             -940,000 -475,000                       
          asset impairment and non-cash mine closure costs
                                                     
          non-cash bankruptcy reorganization items
                                                     
          withdrawals (deposits) of restricted cash
                                2,066,000                     
          increase in cash and cash equivalents
                                42,208,000       29,840,000    -779,155,000   -42,883,000 29,583,000   8,154,000 1,691,000  
          cash and cash equivalents, beginning of period
                                305,372,000 784,622,000 138,149,000 93,593,000  61,138,000  70,649,000  5,080,000  
          cash and cash equivalents, end of period
                                347,580,000 730,119,000 394,757,000 117,770,000 76,164,000 13,125,000 69,220,000  6,787,000 6,592,000 50,374,000  789,733,000 22,794,000 27,766,000  39,905,000 -12,073,000 13,234,000  1,696,000 
          amortization of acquired sales contracts
                                     1,489,000 5,944,000 9,601,000 10,038,000 5,214,000 10,753,000           
          expenses related to proposed debt restructuring
                                                     
          additions to prepaid royalties
                                      -20,915,000 -3,640,000 -249,000 -126,000 -23,340,000 -3,881,000 -350,000 -2,209,000 -20,315,000 -335,000 -350,000 -19,079,000 -340,000 -350,000 
          proceeds from (consideration paid for) disposals and divestitures
                                                     
          purchases of marketable securities
                                                     
          proceeds from sale or maturity of marketable securities and other investments
                                                     
          deposits of restricted cash
                                                     
          decrease in cash and cash equivalents
                                      -24,373,000   6,592,000 -10,764,000           
          losses from disposed operations resulting from patriot coal bankruptcy
                                                     
          amortization of premiums on debt securities held
                                                     
          coal derivative assets and liabilities
                                    10,297,000 5,989,000 -1,087,000 -4,562,000 2,485,000 6,084,000 5,547,000 10,355,000 5,081,000 5,532,000 11,298,000 16,746,000 30,840,000 -59,172,000 -29,597,000   
          proceeds from dispositions of property, plant and equipment
                                 714,000 446,000 22,105,000 23,722,000 895,000 516,000 78,000 23,000 134,000 95,000 19,000 91,000 501,000 214,000 66,000 -1,000 648,000 422,000 436,000 19,000 
          change in restricted cash
                                 1,163,000                    
          net increase in borrowings under lines of credit
                                                     
          payments on term note
                                                     
          proceeds from exercise of options under incentive plans
                                                     
          bridge financing costs related to icg
                                                    
          net income resulting from early retirement of debt and refinancing activities
                                                     
          noncash mine closure and asset impairment costs
                                                     
          goodwill impairment
                                                     
          acquisition of icg, net of cash acquired
                                                     
          purchases of investments and advances to affiliates
                                      -34,419,000 -29,445,000 -2,491,000 -4,178,000 -10,071,000 -572,000 -890,000 -3,582,000 -5,881,000  -1,365,000 -2,182,000 -812,000   
          proceeds from the issuance of senior notes
                                                    
          proceeds from term note
                                                     
          proceeds from the issuance of common stock
                                    18,369,000                 
          payments to retire debt
                                                     
          net increase in borrowings under lines of credit and commercial paper program
                                   34,000,000 -20,000,000 299,415,000 3,681,000 -78,212,000 -102,782,000 3,769,000 -19,324,000 -90,160,000 -130,004,000         
          issuance of common stock under incentive plans
                                  5,131,000 782,000 78,000 768,000 1,425,000 202,000 52,000 85,000 26,000 58,000 13,000 18,000 4,125,000 2,163,000 3,236,000 200,000 
          decrease in restricted cash
                                   1,455,000                  
          net income resulting from early retirement of debt
                                                     
          write down of assets acquired from icg
                                                    
          gain on knight hawk transaction
                                                   
          increase in restricted cash
                                                     
          contribution from noncontrolling interest
                                                   
          net income resulting from early retirement of icg debt
                                                     
          amortization of debt financing costs
                                     2,651,000 2,442,000 2,444,000              
          payments to retire icg debt
                                                     
          increase in restricted cash for retirement of icg debt
                                                     
          employee stock-based compensation
                                      5,290,000 2,077,000 2,201,000 3,755,000 3,684,000 3,141,000 3,352,000 3,381,000 3,520,000 2,850,000 2,847,000 3,287,000 3,634,000 1,727,000 1,375,000 
          loss on early retirement of debt
                                                     
          changes in operating assets and liabilities:
                                                     
          accrued postretirement benefits other than pension
                                                     
          accrued workers’ compensation
                                                     
          payments made to acquire jacobs ranch
                                                     
          consideration paid related to prior business acquisitions
                                                     
          reimbursement of deposits on equipment
                                            3,209,000  242,000    
          proceeds from the issuance of long-term debt
                                                   
          repayments of long-term debt, including redemption premium
                                                    
          proceeds from the sale of common stock
                                                    
          net proceeds from (payments on) other debt
                                                     
          cash and cash equivalents, beginning of year
                                                     
          cash and cash equivalents, end of year
                                                     
          supplemental cash flow information:
                                                     
          cash paid during the year for interest
                                                     
          cash paid during the year for income taxes
                                                     
          loss on early extinguishment of debt
                                                     
          gain on dispositions of property, plant and equipment
                                         -128,000 17,000  205,000 -232,000 -54,000  1,000 220,000 -399,000   
          net (gain) loss on dispositions of property, plant and equipment
                                                     
          other non-operating expense
                                                   147,000 806,000 
          reimbursement of deposit on equipment
                                                     
          cash (paid) received during the year for income taxes
                                                     
          net proceeds from commercial paper and net borrowings on lines of credit
                                              137,265,000 -37,389,000 9,866,000 -109,630,000 150,646,000 -632,000  
          gain on investment in knight hawk holdings, llc
                                                     
          purchases of investments/advances to affiliates
                                                   -388,000  
          accounts payable and accrued expenses
                                                -23,418,000 36,214,000 16,025,000 16,649,000 -37,064,000 
          cash received during the year for income taxes
                                                     
          net gain on dispositions of property, plant and equipment
                                                    -886,000 
          payments on long-term debt
                                                    -2,283,000 
          advances to affiliates
                                                     
          net borrowings on revolver and lines of credit