7Baggers

NACCO Industries, Inc
(NYSE:NC) 

NC stock logo

NACCO Industries, Inc., together with its subsidiaries, engages in the mining and natural resources businesses. The company operates through three segments: Coal Mining, North American Mining, and Minerals Management. The Coal Mining segment operates surface coal mines under long-term contracts with...

Founded: 1913
Full Time Employees: 400
Sector: Energy
Industry: Thermal Coal

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Quarterly
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    Unit: USD2026-03-31 2025-12-31 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 2021-09-30 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 2010-06-30 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 2006-09-30 2006-06-30 2006-03-31 2005-12-31 2005-09-30 2005-06-30 2005-03-31 2004-12-31 2004-09-30 2004-06-30 2004-03-31 2003-12-31 
                                                                                          
      revenues
    62,775,000 66,778,000 76,614,000 68,235,000 65,571,000 70,418,000 61,656,000 52,345,000 53,289,000 56,757,000 46,546,000 61,350,000 50,141,000 63,534,000 61,793,000 61,369,000 55,023,000 51,742,000 45,896,000 45,105,000 23,138,000 32,295,000 35,355,000 37,644,000 26,938,000 32,603,000 41,352,000 40,097,000 24,080,250 31,440,000 33,681,000 31,200,000 19,585,250 21,941,000 181,076,000 168,582,000 284,218,000 220,792,000 178,007,000 173,421,000 286,519,000 239,107,000 196,500,000 193,734,000 297,285,000 221,714,000 200,370,000 177,413,000 311,983,000 228,614,000 196,017,000 196,052,000 318,200,000 210,100,000 773,400,000 803,200,000 951,300,000 823,400,000 811,000,000 745,500,000 598,800,000 557,600,000 674,200,000 532,600,000 545,200,000 558,600,000 949,400,000 917,800,000 948,100,000 865,000,000 1,092,700,000 875,200,000 830,900,000 803,900,000             
      cost of sales
    48,484,000 54,750,000 66,643,000 61,415,000 55,917,000 61,942,000 54,412,000 45,327,000 46,271,000 49,756,000 48,720,000 54,943,000 46,784,000 45,010,000 43,965,000 45,726,000 39,176,000 37,413,000 36,911,000 37,413,000 21,910,000 25,475,000 31,515,000 32,563,000 24,050,000 26,416,000 32,684,000 26,712,000 19,989,000 25,345,000 28,835,000 25,776,000 16,677,750 19,466,000 137,648,000 129,447,000 210,607,000 169,084,000 137,478,000 133,416,000 222,808,000 196,892,000 161,119,000 155,545,000 231,450,000 175,171,000 163,847,000 141,242,000 233,802,000 179,395,000 148,387,000 149,791,000 233,400,000 157,800,000 633,300,000 658,600,000 770,200,000 685,900,000 673,100,000 608,900,000 475,700,000 451,900,000 539,300,000 438,300,000 452,100,000 472,800,000 809,700,000 813,900,000 826,000,000 737,400,000 904,400,000 724,600,000 701,500,000 672,900,000 669,200,000 666,800,000 649,000,000 750,000,000 623,200,000 653,800,000 617,200,000 701,200,000 555,800,000 538,100,000 509,800,000  
      gross profit
    14,291,000 12,028,000 9,971,000 6,820,000 9,654,000 8,476,000 7,244,000 7,018,000 7,018,000 7,001,000 -2,174,000 6,407,000 3,357,000 18,524,000 17,828,000 15,643,000 15,847,000 14,329,000 8,985,000 7,692,000 1,228,000 6,820,000 3,840,000 5,081,000 2,888,000 6,187,000 8,668,000 13,385,000 13,603,000 6,095,000 4,846,000 5,424,000 5,289,000 2,475,000 43,428,000 39,135,000 73,611,000 51,708,000 40,529,000 40,005,000 63,711,000 42,215,000 35,381,000 38,189,000 65,835,000 46,543,000 36,523,000 36,171,000 78,181,000 49,219,000 47,630,000 46,261,000 84,800,000 52,300,000 140,100,000 144,600,000 181,100,000 137,500,000 137,900,000 136,600,000 123,100,000 105,700,000 134,900,000 94,300,000 93,100,000 85,800,000 139,700,000 103,900,000 122,100,000 127,600,000 188,300,000 150,600,000 129,400,000 131,000,000 133,900,000 130,100,000 121,400,000 156,800,000 121,100,000 124,700,000 110,600,000 154,900,000 112,200,000 106,200,000 104,400,000  
      yoy
    48.03% 41.91% 37.64% -2.82% 37.56% 21.07% -433.21% 9.54% 109.06% -62.21% -112.19% -59.04% -78.82% 29.28% 98.42% 103.37% 1190.47% 110.10% 133.98% 51.39% -57.48% 10.23% -55.70% -62.04% -78.77% 1.51% 78.87% 146.77% 157.19% 146.26% -88.84% -86.14% -92.81% -95.21% 7.15% -2.17% 15.54% 22.49% 14.55% 4.76% -3.23% -9.30% -3.13% 5.58% -15.79% -5.44% -23.32% -21.81% -7.81% -5.89% -66.00% -68.01% -53.18% -61.96% 1.60% 5.86% 47.12% 30.09% 2.22% 44.86% 32.22% 23.19% -3.44% -9.24% -23.75% -32.76% -25.81% -31.01% -5.64% -2.60% 40.63% 15.76% 6.59% -16.45% 10.57% 4.33% 9.76% 1.23% 7.93% 17.42% 5.94%      
      qoq
    18.81% 20.63% 46.20% -29.36% 13.90% 17.01% 3.22% 0.00% 0.24% -422.03% -133.93% 90.85% -81.88% 3.90% 13.97% -1.29% 10.59% 59.48% 16.81% 526.38% -81.99% 77.60% -24.42% 75.93% -53.32% -28.62% -35.24% -1.60% 123.18% 25.77% -10.66% 2.55% 113.70% -94.30% 10.97% -46.84% 42.36% 27.58% 1.31% -37.21% 50.92% 19.32% -7.35% -41.99% 41.45% 27.43% 0.97% -53.73% 58.84% 3.34% 2.96% -45.45% 62.14% -62.67% -3.11% -20.15% 31.71% -0.29% 0.95% 10.97% 16.46% -21.65% 43.05% 1.29% 8.51% -38.58% 34.46% -14.91% -4.31% -32.24% 25.03% 16.38% -1.22% -2.17% 2.92% 7.17% -22.58% 29.48% -2.89% 12.75% -28.60% 38.06% 5.65% 1.72%   
      gross 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% 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% 16.84% 16.49% 15.91% 17.44% 16.40% 16.13% 15.29% 18.21% 16.91% 16.61% 17.10%  
      earnings of unconsolidated operations
    16,571,000 16,205,000 16,494,000 13,138,000 15,986,000 15,422,000 15,155,000 13,592,000 13,307,000 12,332,000 12,754,000 11,084,000 13,824,000 13,448,000 14,588,000 14,622,000 14,592,000 17,652,000 13,542,000 15,342,000 15,277,000 15,145,000 13,778,000 16,003,000 16,032,000 17,438,000 14,143,000 16,270,000 16,875,000 17,141,000 15,423,000 15,555,000                                                       
      operating expenses
                                                                                          
      selling, general and administrative expenses
    19,701,000 20,661,000 19,549,000 19,773,000 17,868,000 20,094,000 16,487,000 17,720,000 15,453,000 19,876,000 16,118,000 14,746,000 14,876,000 15,496,000 17,790,000 15,841,000 14,784,000 13,830,000 12,878,000 13,763,000 15,911,000 11,833,000 12,591,000 12,727,000 14,001,000 14,341,000 12,788,000 12,653,000 14,670,000 12,032,000 11,863,000 10,627,000 15,682,000 11,723,000 47,999,000 45,790,000 56,612,000 47,504,000 47,528,000 46,259,000 54,739,000 47,551,000 45,219,000 46,416,000 52,905,000 46,373,000 50,990,000 48,429,000 57,580,000 43,317,000 48,484,000 50,991,000 60,300,000 52,100,000 121,500,000 118,800,000 124,400,000 111,100,000 116,400,000 113,400,000 104,800,000 94,000,000 107,200,000 94,700,000 88,300,000 98,100,000 122,900,000 108,900,000 119,700,000 124,000,000 126,700,000 122,900,000 119,800,000 122,900,000 112,100,000 105,400,000 109,100,000 119,400,000 102,700,000 107,400,000 106,800,000 114,100,000 100,100,000 100,500,000 98,900,000  
      amortization of intangible assets
    151,000 176,000 167,000 245,000 162,000 158,000 131,000 116,000 126,000 702,000 642,000 927,000 727,000 947,000 867,000 1,058,000 847,000 902,000 911,000 982,000 269,000 734,000 792,000 777,000 371,000 715,000 881,000 647,000 826,000 714,000 814,000 684,000 482,000 435,000 964,000 932,000 912,000 1,164,000 826,000 982,000 814,000 1,138,000 950,000 1,085,000 633,000 911,000 991,000 765,000 932,000 1,076,000 619,000                                    
      gain on sale of assets
    -6,000 -177,000 -28,000 -9,000 -72,000    -11,000    -236,000    -136,000   -41,000 -22,000  -247,000  -75,000 -94,000 -19,000 -18,000 -572,000 -57,000 -210,000 -53,000                     -1,400,000 -3,100,000 -2,300,000       -100,000 -1,800,000 -6,000,000 -500,000 -1,700,000                     
      operating expenses - sum
    19,846,000 20,660,000 19,688,000 20,009,000 17,958,000 20,015,000 16,312,000 13,244,000 15,568,000 86,767,000 16,847,000 15,741,000 15,367,000 16,431,000 22,598,000 14,582,000 15,495,000 14,722,000 13,857,000 14,704,000 24,517,000 12,567,000 13,136,000 13,504,000 14,297,000 14,962,000 13,650,000 13,282,000 14,924,000 12,689,000 12,467,000 11,258,000 15,516,000 11,683,000 46,322,000 46,722,000 57,670,000 66,111,000 48,354,000 47,241,000 53,742,000 48,689,000 46,169,000 47,501,000 151,318,000 47,284,000 51,981,000 49,194,000 61,594,000 44,345,000 49,108,000 51,337,000                                   
      operating profit
    11,016,000 7,573,000 6,777,000 -51,000 7,682,000 3,883,000 19,699,000 7,366,000 4,757,000 -67,434,000 -6,267,000 1,750,000 1,814,000 15,541,000 9,818,000 29,683,000 14,944,000 27,592,000 8,670,000 8,330,000 -8,012,000 9,398,000 4,482,000 7,580,000 4,623,000 8,663,000 9,161,000 16,373,000 15,554,000 10,547,000 7,802,000 9,721,000 6,507,000 6,989,000 10,581,000 7,368,000 30,394,000 699,000 5,210,000 5,412,000 21,538,000 5,760,000 1,288,000 3,241,000 -73,156,000 11,323,000 -3,891,000 -585,000 28,829,000 16,682,000 8,803,000 7,022,000 37,000,000 14,800,000 31,500,000 37,800,000 70,300,000 37,400,000 31,100,000 35,300,000 27,300,000 24,200,000 37,100,000 9,200,000 13,600,000 -800,000 -412,800,000 3,000,000 10,900,000 11,600,000 71,200,000 34,000,000 17,200,000 15,000,000 31,600,000 33,800,000 25,100,000 42,500,000 27,800,000 25,500,000 12,200,000 47,900,000 20,800,000 14,000,000 5,300,000  
      yoy
    43.40% 95.03% -65.60% -100.69% 61.49% -105.76% -414.33% 320.91% 162.24% -533.91% -163.83% -94.10% -87.86% -43.68% 13.24% 256.34% -286.52% 193.59% 93.44% 9.89% -273.31% 8.48% -51.08% -53.70% -70.28% -17.86% 17.42% 68.43% 139.03% 50.91% -26.26% 31.94% -78.59% 899.86% 103.09% 36.14% 41.12% -87.86% 304.50% 66.99% -129.44% -49.13% -133.10% -654.02% -353.76% -32.12% -144.20% -108.33% -22.08% 12.72% -72.05% -81.42% -47.37% -60.43% 1.29% 7.08% 157.51% 54.55% -16.17% 283.70% 100.74% -3125.00% -108.99% 206.67% 24.77% -106.90% -679.78% -91.18% -36.63% -22.67% 125.32% 0.59% -31.47% -64.71% 13.67% 32.55% 105.74% -11.27% 33.65% 82.14% 130.19%      
      qoq
    45.46% 11.75% -13388.24% -100.66% 97.84% -80.29% 167.43% 54.85% -107.05% 976.02% -458.11% -3.53% -88.33% 58.29% -66.92% 98.63% -45.84% 218.25% 4.08% -203.97% -185.25% 109.68% -40.87% 63.96% -46.64% -5.44% -44.05% 5.27% 47.47% 35.18% -19.74% 49.39% -6.90% -33.95% 43.61% -75.76% 4248.21% -86.58% -3.73% -74.87% 273.92% 347.20% -60.26% -104.43% -746.08% -391.00% 565.13% -102.03% 72.82% 89.50% 25.36% -81.02% 150.00% -53.02% -16.67% -46.23% 87.97% 20.26% -11.90% 29.30% 12.81% -34.77% 303.26% -32.35% -1800.00% -99.81% -13860.00% -72.48% -6.03% -83.71% 109.41% 97.67% 14.67% -52.53% -6.51% 34.66% -40.94% 52.88% 9.02% 109.02% -74.53% 130.29% 48.57% 164.15%   
      operating 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% 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% 3.97% 4.28% 3.29% 4.73% 3.76% 3.30% 1.69% 5.63% 3.13% 2.19% 0.87%  
      other expense
                                                                                          
      interest expense
    1,658,000 949,000 1,087,000 1,944,000 1,774,000 1,758,000 1,386,000 1,311,000 1,111,000 711,000 632,000 572,000 545,000 539,000 486,000 496,000 513,000 493,000 359,000 356,000 285,000 336,000 330,000 403,000 189,000 230,000 222,000 231,000 362,000 421,000 569,000 646,000 634,000 946,000 1,390,000 1,347,000 1,395,000 1,322,000 1,470,000 1,505,000 1,541,000 1,597,000 1,661,000 2,125,000 2,116,000 2,046,000 1,950,000 1,454,000 1,279,000 1,044,000 1,148,000 1,304,000 1,400,000 1,500,000 4,900,000 5,500,000 5,800,000 6,400,000 6,100,000 6,200,000 -6,900,000 -6,800,000 -7,900,000 -8,300,000 -7,800,000 -8,200,000 -9,000,000 -9,900,000 -10,700,000 -11,000,000 -11,600,000 -11,300,000 -9,800,000 -8,000,000 -7,900,000 -10,800,000 -13,500,000 -12,000,000 -12,200,000 -11,700,000 -11,600,000 -11,600,000 -11,700,000 -12,000,000 -12,100,000  
      interest income
    -595,000 -709,000 -708,000 -770,000 -865,000 -1,179,000 -1,084,000 -1,038,000 -1,127,000 -1,533,000 -1,679,000 -1,714,000 -1,155,000 -757,000 -352,000 -195,000 -145,000 -101,000 -100,000 -120,000 -575,000 -95,000 -129,000 -401,000 -604,000 -1,878,000 -581,000 -553,000                                   500,000 1,000,000 900,000 800,000 1,200,000 1,600,000 1,700,000 3,100,000                 
      closed mine obligations
    489,000 -997,000 478,000 503,000 473,000 992,000 463,000 471,000 455,000 2,349,000 394,000 433,000 409,000 24,000 398,000 377,000 380,000 372,000 364,000 383,000 422,000 395,000 390,000 434,000 458,000 383,000 330,000 366,000 303,000 272,000 343,000 379,000 519,000 336,000 352,000 383,000 -1,162,000 223,000 349,000 376,000 -152,000 244,000 425,000 402,000 1,642,000 316,000 308,000 316,000 874,000 266,000 272,000 405,000                                   
      loss on equity securities
    -455,000 489,000 -284,000 -349,000 870,000 -304,750 -442,000 264,000  -1,460,000 551,000 -421,000  -1,393,000 316,000 1,878,000    -823,000    1,196,000    -698,000                                                           
      other
    92,000 -29,000 247,000 217,000 303,000 185,000 244,000 130,000 -214,000 -1,568,000 -315,000 -377,000 -1,725,000 940,000 -354,000 -1,064,000 -230,000 -161,000 -127,000 -130,000 41,000 -1,064,000 -102,000 -15,000 709,000 -1,258,000 11,000 11,000                        -133,000 -200,000 -300,000 1,100,000 -1,400,000 3,300,000 -900,000 -1,300,000 -700,000 1,000,000  1,100,000 300,000 -100,000 300,000   -200,000 -2,100,000 -6,800,000 1,700,000 2,200,000 200,000 1,200,000 200,000 2,700,000    -100,000      
      other expense - sum
    1,189,000 7,507,000 820,000 -2,045,000 2,555,000 1,170,000 567,000 1,138,000 -816,000 -1,501,000 -417,000 -1,507,000  -685,000 -1,662,000 -15,390,000  158,000 -766,000 -334,000 -711,000 -481,000 -1,102,000 1,484,000 -54,000 -2,958,000 -602,000 -965,000 610,000 -111,000 221,000 741,000 752,000 1,033,000 1,105,000 720,000 396,000 1,685,000 3,533,000 1,631,000 1,090,000 2,485,000 1,619,000 1,834,000 4,098,000 2,257,000 2,405,000 1,504,000 1,673,000 1,198,000 1,560,000 1,185,000                                   
      income before income tax provision
    9,827,000 3,269,500 5,957,000 1,994,000 5,127,000 7,733,250 19,132,000 6,228,000 5,573,000 -65,933,000 -5,850,000 3,257,000 4,368,000 16,226,000 11,480,000 45,073,000 14,944,000 27,434,000 9,436,000  -7,301,000 9,879,000 5,584,000 6,096,000 4,677,000 11,621,000 9,763,000 17,338,000       9,476,000 6,648,000 29,998,000 -986,000 1,677,000 3,781,000 20,448,000 3,275,000 -331,000 1,407,000 170,250 9,066,000 -6,296,000 -2,089,000                                       
      income tax provision
    991,000 -2,084,000 -7,297,000 -1,266,000 227,000 1,189,000 3,497,000 256,000 1,003,000 -21,966,000 -2,018,000 737,000 -1,324,000 2,444,000 866,000 7,893,000 2,362,000 2,597,000 2,931,000  -1,856,000 1,857,000 -466,000 -70,000 -1,698,000 1,357,000 1,788,000 2,320,000       2,688,000 1,670,000 5,867,000 -544,000 -1,439,000 979,000 2,357,000 134,000 -56,000 380,000 -36,585,000 1,367,000 -2,672,000 -565,000 4,600,000 3,159,000 2,096,000 1,415,000 9,100,000 3,400,000 3,700,000 8,500,000 14,100,000 6,200,000 7,200,000 24,200,000 900,000 3,400,000 9,600,000 5,500,000 5,000,000 400,000 3,900,000 13,200,000 800,000 700,000 13,800,000 5,400,000 1,700,000 2,200,000 7,500,000 2,400,000 3,000,000 7,600,000 3,300,000 4,100,000 -1,900,000 6,000,000 3,700,000 -2,500,000 -1,900,000  
      net income
    8,836,000 -3,840,000 13,254,000 3,260,000 4,900,000 7,564,000 15,635,000 5,972,000 4,570,000 -43,967,000 -3,832,000 2,520,000 5,692,000 13,782,000 10,614,000 37,180,000 12,582,000 24,837,000 6,505,000 8,961,000 -5,445,000 8,022,000 6,050,000 6,166,000 6,375,000 10,264,000 7,975,000 15,018,000 11,016,000 9,200,000 6,393,000 8,176,000 10,173,000 8,398,000 6,788,000 4,978,000 24,131,000 -442,000 3,116,000 2,802,000 18,091,000 3,141,000 -275,000 1,027,000 -40,669,000 7,699,000 -3,624,000 -1,524,000 22,556,000 12,325,000 5,147,000 4,422,000 23,700,000 38,000,000 21,800,000 25,200,000 54,500,000 25,700,000 19,100,000 62,800,000 16,000,000 11,600,000 42,700,000 -4,000,000 1,400,000 -9,100,000 -425,300,000 -17,400,000 2,400,000 2,700,000 51,700,000 21,100,000 9,900,000 6,600,000 18,800,000 4,700,000 12,700,000 32,400,000 13,600,000 11,300,000 5,200,000 32,600,000 13,400,000 6,400,000 -4,500,000  
      yoy
    80.33% -150.77% -15.23% -45.41% 7.22% -117.20% -508.01% 136.98% -19.71% -419.02% -136.10% -93.22% -54.76% -44.51% 63.17% 314.91% -331.07% 209.61% 7.52% 45.33% -185.41% -21.84% -24.14% -58.94% -42.13% 11.57% 24.75% 83.68% 8.29% 9.55% -5.82% 64.24% -57.84% -2000.00% 117.84% 77.66% 33.39% -114.07% -1233.09% 172.83% -144.48% -59.20% -92.41% -167.39% -280.30% -37.53% -170.41% -134.46% -4.83% -67.57% -76.39% -82.45% -56.51% 47.86% 14.14% -59.87% 240.63% 121.55% -55.27% -1670.00% 1042.86% -227.47% -110.04% -77.01% -41.67% -437.04% -922.63% -182.46% -75.76% -59.09% 175.00% 348.94% -22.05% -79.63% 38.24% -58.41% 144.23% -0.61% 1.49% 76.56% -215.56%      
      qoq
    -330.10% -128.97% 306.56% -33.47% -35.22% -51.62% 161.81% 30.68% -110.39% 1047.36% -252.06% -55.73% -58.70% 29.85% -71.45% 195.50% -49.34% 281.81% -27.41% -264.57% -167.88% 32.60% -1.88% -3.28% -37.89% 28.70% -46.90% 36.33% 19.74% 43.91% -21.81% -19.63% 21.14% 23.72% 36.36% -79.37% -5559.50% -114.18% 11.21% -84.51% 475.96% -1242.18% -126.78% -102.53% -628.24% -312.44% 137.80% -106.76% 83.01% 139.46% 16.40% -81.34% -37.63% 74.31% -13.49% -53.76% 112.06% 34.55% -69.59% 292.50% 37.93% -72.83% -1167.50% -385.71% -115.38% -97.86% 2344.25% -825.00% -11.11% -94.78% 145.02% 113.13% 50.00% -64.89% 300.00% -62.99% -60.80% 138.24% 20.35% 117.31% -84.05% 143.28% 109.38% -242.22%   
      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% 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% 2.36% 0.60% 1.66% 3.60% 1.84% 1.46% 0.72% 3.83% 2.02% 1.00% -0.74%  
      earnings per share:
                                                                                          
      basic earnings per share
    1.18 -0.52 1.78 0.44 0.67 1.03 2.14 0.81 0.61 -5.88 -0.51 0.34 0.77 1.87 1.45 5.07 1.73 3.47 0.91 1.26 -0.77 1.14 0.86 0.88 0.91 1.47 1.14 2.16 1.59 1.33 0.92 1.19 1.49 1.23 0.99 0.73 3.54 -0.07 0.45 0.41 2.59 0.45 -0.04 0.14 -5.35 1.02 -0.47 -0.19 2.8 1.54 0.63 0.53 2.83 4.53 2.6 3.01 6.49 3.06 2.29 7.51 1.91 1.41         1.138 2.55   2.28            
      diluted earnings per share
    1.17 -0.52 1.78 0.44 0.66 1.01 2.14 0.81 0.61 -5.87 -0.51 0.34 0.76 1.82 1.45 5.07 1.72 3.47 0.91 1.25 -0.78 1.14 0.86 0.88 0.9 1.47 1.14 2.15 1.57 1.33 0.92 1.18 1.47 1.23 0.99 0.73 3.52 -0.07 0.45 0.41 2.58 0.45 -0.04 0.14 -5.35 1.02 -0.47 -0.19 2.8 1.54 0.63 0.53 2.8 4.52 2.6 6.47 3.05 2.28 7.48 1.91 1.4         1.138 2.55   2.28            
      basic weighted-average shares outstanding
    7,482 7,423 7,454 7,445 7,363 7,363 7,312 7,394 7,452 7,478 7,517 7,513 7,428 7,312 7,337 7,330 7,253 7,165 7,153 7,101 7,026 7,036 7,024 7,000 6,974 6,991 6,986 6,949 6,924 6,940 6,940 6,894 6,830 6,839 6,835 6,806 6,818 6,786 6,856 6,857 7,001 6,924 7,048 7,189 7,590 7,515 7,712 7,848 8,105 7,988 8,179 8,360  8.391 8.388 8.379  8.395 8.393 8.363 8.331 8.321   8.289 8.287  8.283 8.282 8.275  8.267 8.267 8.252 8.237 8.236 8.229          
      diluted weighted-average shares outstanding
    7,552 7,481 7,454 7,445 7,447 7,411 7,312 7,394 7,515 7,478 7,517 7,513 7,515 7,373 7,337 7,330 7,321 7,165 7,153 7,142 7,057 7,036 7,024 7,040 7,007 6,991 6,986 6,998 6,960 6,940 6,940 6,939 6,873 6,866 6,850 6,843 6,854 6,786 6,874 6,885 7,022 6,935 7,048 7,208 7,590 7,533 7,718 7,860 8,124 7,996 8,184 8,399  8.409 8.4 8.394  8.416 8.407 8.399 8.338 8.331   8.294 8.287  8.283 8.288 8.282  8.274 8.27 8.267 8.246 8.24 8.232          
      business interruption insurance recoveries
          13,612,000                                                                                
      gain on settlement of excess funding liability
       -3,590,000                                                                                   
      loss on sale of assets
         -237,000 -306,000 -4,592,000  302,000 87,000 68,000  -612,750 2,000 -2,317,000  -10,000 68,000              -1,630,000 -475,000 -2,641,000              75,750 -48,000 5,000 346,000      100,000 -100,000  500,000                          
      gain on equity securities
            -1,041,000    -628,000    -518,000 -445,000 -1,262,000  -875,000 -35,000 -1,512,000  -266,750 -108,000 -261,000                                                            
      contract termination settlement
                   14,000,000  10,333,000                                                                     
      asset impairment charges
                  3,939,000                                                                        
      income from equity method investee
                 -38,000 -2,156,000                                                                        
      other contract termination settlements
                   -16,882,000                                                                       
      income before income tax benefit
                       8,664,000                                                                   
      income tax benefit
                       -297,000                                                                   
      income from other unconsolidated affiliates
                        -9,000 -18,000 -79,000 -133,000 -328,000 -327,000 -323,000 -322,000 -322,000 -321,000 -318,000 -315,000 -314,000 -313,000 -311,000 -308,000 -308,000 -307,000 -303,000 -303,000 -304,000 -264,000 -300,000 -1,172,000 -2,000 -191,000  -388,000 -419,000 -286,000 -336,000 -391,000            -700,000 -200,000 -800,000 -100,000 1,300,000 1,600,000 1,800,000 2,500,000 2,100,000 2,000,000 1,500,000 1,400,000 1,400,000 900,000 2,600,000 900,000 1,500,000 2,300,000 2,000,000 1,100,000 1,800,000 800,000  
      other, net, including interest income
                                267,000 -483,000 -373,000 31,000 -87,000 64,000 -326,000 -702,000 471,000 447,000 2,017,000 53,000 5,000 908,000 -167,000 479,000 342,000 86,000 -273,000 122,000                                       
      income from continuing operations before income tax provision
                                14,944,000 10,658,000 7,581,000 8,980,000 5,755,000 5,956,000               27,156,000 15,484,000 7,243,000 5,837,000                                   
      income tax provision from continuing operations
                                3,928,000 1,458,000 1,188,000 804,000 -3,925,000 2,625,000                                                     
      income from continuing operations
                                11,016,000 9,200,000 6,393,000 8,176,000 9,680,000 3,331,000                   23,700,000 10,200,000       16,000,000                          
      discontinued operations, net of tax expense of 236 and 2,655 in the three and nine months ended september 30, 2017, respectively.
                                                                                          
      basic earnings per share:
                                                                                          
      continuing operations
                                1.59 1.33 0.92 1.19 1.42 0.49               2.8 1.54 0.63 0.53 2.83 1.22       1.91                          
      discontinued operations
                                    0.07 0.74                    3.31                                 
      diluted earnings per share:
                                                                                          
      dividends per share
                                0.124 0.165 0.165 0.165 0.203 0.273 0.273 0.268 0.199 0.268 0.268 0.263 0.196 0.263 0.263 0.258 0.191 0.258 0.258 0.25 0.188 0.25 0.25 0.25 0.407 0.548 0.548 0.533 0.397 0.533 0.533 0.523 0.523 0.518 0.388 0.518 0.518 0.515 0.383 0.515 0.515 0.5 0.37 0.5 0.5 0.48 0.48 0.48 0.465 0.346 0.465 0.465 0.453 0.306 0.453 0.39 0.38  
      discontinued operations, net of tax expense of 2,443 and 3,514 in the three and six months ended june 30, 2017, respectively.
                                                                                          
      discontinued operations, net of tax expense of 1,071 in the three months ended march 31, 2017
                                                                                          
      earnings of unconsolidated mines
                                    16,734,000 16,197,000 13,475,000 14,955,000 14,453,000 15,102,000 13,035,000 12,648,000 11,569,000 12,234,000 12,076,000 12,553,000 12,327,000 12,064,000 11,567,000 12,438,000 12,242,000 11,808,000 10,281,000 12,098,000 11,100,000 11,500,000 10,600,000 12,000,000 12,800,000 11,100,000 9,500,000 12,100,000 9,500,000 10,500,000 7,800,000 10,500,000                       
      centennial asset impairment charge
                                         17,443,000                                                 
      discontinued operations, net of tax expense of 236 and 2,655 in the three and nine months ended september 30, 2017, respectively, and net of tax expense of 11,044 and 12,966 in the three and nine months ended september 30, 2016, respectively.
                                    345,250 5,067,000                                                     
      loss from other unconsolidated affiliates
                                                  420,000                                        
      other net, including interest income
                                                    129,250 174,000 476,000                                    
      income from continuing operations, net of tax
                                                    22,556,000 12,325,000 5,147,000 4,422,000         15,900,000                          
      income from discontinued operations, net of 1,154 tax benefit and 7,599 tax expense in the three and nine months ended september 30, 2012, respectively
                                                                                          
      income from discontinued operations, net of tax expense of 2,237 and 8,752 in the three and six months ended june 30, 2012, respectively
                                                                                          
      income from discontinued operations, net of tax expense of 6,425
                                                                                          
      applica settlement and litigation costs
                                                               -57,200,000                           
      income before income taxes
                                                        32,800,000 13,600,000 25,500,000 33,700,000 68,600,000 31,900,000 26,300,000 87,000,000 16,900,000 15,000,000 29,700,000 1,500,000 6,400,000 -8,700,000                     
      discontinued operations, net of 1.3 tax benefit and 7.6 tax expense in three and nine months ended september 30, 2012, respectively, and net of 4.1 and 15.8 tax expense in three and nine months ended september 30, 2011, respectively.
                                                        16,625,000 27,800,000                                 
      comprehensive income
                                                        22.1 48.9 9.5 37,700,000 35,700,000 10,300,000 28,400,000 72,100,000 2,300,000  30,200,000 1,400,000 35,600,000 -11,900,000 -498,600,000 -45,500,000 16,900,000 10,200,000 63,000,000 28,900,000 20,100,000 11,600,000 17,400,000 15,800,000 19,400,000 19,700,000 13,500,000 -900,000 -3,000,000 47,400,000 17,800,000 3,300,000 -4,400,000  
      net loss attributable to noncontrolling interest
                                                            25,000  100,000  -100,000 100,000 -200,000 100,000 200,000                      
      net income attributable to stockholders
                                                          21,800,000 25,200,000 54,400,000 25,700,000 19,200,000 62,800,000 15,900,000 11,700,000   1,600,000                      
      restructuring reversal
                                                                                -200,000          
      restructuring charges
                                                                 -1,900,000 200,000 6,900,000 1,500,000 700,000            3,200,000  -500,000  300,000 -300,000 -1,100,000 8,700,000  
      other income
                                                                                          
      unsuccessful merger costs
                                                                -4,500,000 -2,400,000                         
      discontinued operations, net of tax
                                                                                          
      amounts attributable to stockholders
                                                                                          
      basic earnings per share attributable to stockholders:
                                                                                          
      diluted earnings per share attributable to stockholders:
                                                                                          
      comprehensive loss
                                                                 -4,800,000                         
      net loss attributable to stockholders
                                                                  -2,850,000 -3,900,000                       
      basic and diluted loss per share
                                                                  -0.345 -0.47                       
      basic and diluted weighted-average shares outstanding
                                                                   8.291                       
      earnings of unconsolidated project mining subsidiaries
                                                                    9,800,000 10,500,000 11,800,000 9,700,000 9,300,000 8,600,000 10,000,000 9,800,000 8,600,000 9,300,000 9,400,000 9,100,000 8,900,000 8,300,000 9,400,000 7,700,000 8,400,000 7,400,000 8,400,000 7,200,000 8,500,000  
      basic and diluted earnings per share
                                                                    0.19 -1.1 -0.373 -2.1 0.29 0.33   1.2 0.8  0.57 1.54          
      gain on sale of businesses
                                                                          200,000 -1,500,000     -3,700,000          
      restructuring charge
                                                                      775,000 1,700,000 800,000 600,000 2,100,000 5,000,000 1,000,000 2,400,000             
      income before income taxes and minority interest
                                                                      675,000 -4,000,000 3,300,000 3,400,000 11,700,000 26,500,000 11,600,000 8,700,000 26,300,000 7,000,000 15,200,000 8,875,000 16,900,000 15,400,000 3,200,000      
      income before minority interest
                                                                      -3,000,000 -17,200,000 2,500,000 2,700,000 9,375,000 21,100,000 9,900,000 6,500,000 18,800,000 4,600,000 12,200,000 7,500,000 13,600,000 11,300,000 5,100,000      
      minority interest income
                                                                      100,000 -200,000 -100,000     100,000  100,000 500,000    100,000 -100,000 100,000 100,000 300,000  
      loss on extinguishment of debt
                                                                               -17,600,000           
      net sales
                                                                              795,100,000 789,000,000 762,900,000 899,100,000 738,400,000 773,100,000 723,400,000 850,400,000 663,500,000 639,200,000 610,500,000  
      yoy
                                                                              7.68% 2.06% 5.46% 5.73% 11.29% 20.95% 18.49%      
      qoq
                                                                              0.77% 3.42% -15.15% 21.76% -4.49% 6.87% -14.93% 28.17% 3.80% 4.70%   
      other revenues
                                                                              8,000,000 7,900,000 7,500,000 7,700,000 5,900,000 5,400,000 4,400,000 5,700,000 4,500,000 5,100,000 3,700,000  
      total revenues
                                                                              803,100,000 796,900,000 770,400,000 906,800,000 744,300,000 778,500,000 727,800,000 856,100,000 668,000,000 644,300,000 614,200,000  
      loss on sale of businesses
                                                                              -400,000            
      restructuring reversals
                                                                                          
      income on interest rate swap agreements
                                                                                 100,000 100,000 -100,000 400,000 150,000  600,000   
      u.s. customs award
                                                                                      6,700,000    
      other — net
                                                                                 100,000 300,000     -600,000 -700,000  
      earnings per share
                                                                                 0.915 1.65 1.37 0.63      
      weighted-average shares outstanding
                                                                                  8.225 8.224 8.219  8.213 8.212 8.208  
      other - net
                                                                                   200,000  -300,000 100,000    
      income before income taxes, minority interest and cumulative effect of accounting change
                                                                                     3,525,000 17,000,000 3,800,000 -6,700,000  
      income before minority interest and cumulative effect of accounting change
                                                                                     3,700,000 13,300,000 6,300,000 -4,800,000  
      income before cumulative effect of accounting change
                                                                                     32,600,000 13,400,000 6,400,000 -4,500,000  
      cumulative effect of accounting change
                                                                                          
      loss on interest rate swap agreements
                                                                                          
    Balance Sheets:
    Quarterly
    Annual
      Unit: USD2026-03-31 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 2021-09-30 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 2010-06-30 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 2004-09-30 2004-06-30 2004-03-31 2003-12-31 
                                                                                            
        assets
                                                                                            
        cash and cash equivalents
      53,161,000 52,657,000 49,402,000 61,884,000 72,833,000 63,052,000 62,361,000 61,844,000 85,109,000 128,167,000 117,016,000 109,637,000 110,748,000 92,754,000 97,113,000 81,620,000 87,507,000 85,012,000 79,132,000 88,450,000 97,567,000 95,546,000 93,726,000 122,892,000 115,061,000 98,423,000 79,058,000 85,257,000 83,050,000 79,952,000 83,403,000 101,600,000 93,938,000 60,209,000 56,426,000 80,648,000 44,266,000 34,257,000 35,718,000 52,499,000 11,847,000 19,323,000 29,312,000 61,135,000 50,598,000 60,907,000 70,070,000 95,390,000 79,353,000 85,058,000 96,870,000 139,900,000 155,700,000 303,200,000 314,900,000 338,600,000 217,600,000 301,500,000 249,800,000 270,000,000 233,300,000 256,200,000 187,600,000 178,800,000 155,800,000 138,300,000 171,500,000 187,500,000 222,300,000 281,400,000 240,100,000 253,800,000 117,200,000 196,700,000 105,600,000 112,000,000 128,800,000 166,500,000 85,000,000 83,400,000 112,800,000 150,400,000 32,200,000 44,800,000 49,900,000 68,900,000 
        trade accounts receivable
      33,398,000 30,889,000 38,861,000 33,981,000 49,706,000 39,098,000 36,635,000 27,958,000 37,429,000 29,738,000 46,047,000 31,039,000 37,940,000 23,603,000 32,143,000 27,226,000 19,127,000 21,277,000 22,301,000 18,894,000 16,507,000 20,335,000 21,122,000  13,540,000 19,043,000 19,341,000  12,955,000                                                          
        accounts receivable from affiliates
      6,295,000 4,295,000 9,135,000 4,391,000 5,793,000 5,807,000 6,377,000 8,361,000 7,860,000 5,005,000 9,590,000 4,476,000 6,638,000 6,672,000 6,427,000 5,804,000 6,377,000 6,933,000 7,513,000 4,764,000 3,722,000 4,715,000 6,377,000 6,411,000 6,107,000 7,232,000 8,805,000 7,999,000 11,517,000 12,664,000 21,693,000 19,919,000 22,964,000    7,360,000 4,450,000 4,590,000 3,085,000 2,793,000 3,137,000 2,119,000 57,421,000 44,339,000 36,351,000 32,247,000 32,636,000 30,551,000 29,029,000 27,642,000 28,100,000                                   
        prepaid profit sharing
      11,205,000 9,580,000 12,041,000 14,490,000                                                                                   
        inventories
      58,799,000 59,890,000 58,569,000 63,146,000 94,608,000 94,436,000 83,399,000 75,755,000 77,000,000 69,216,000 65,210,000 71,246,000 71,488,000 61,799,000 56,956,000 55,967,000 50,955,000 49,716,000 45,102,000 47,551,000 42,433,000 35,732,000 35,996,000 40,465,000 33,087,000 30,876,000 32,799,000 31,209,000 33,182,000 29,159,000 30,115,000 30,015,000 30,580,000 163,759,000 158,982,000 157,342,000 201,309,000 167,589,000 164,334,000 165,016,000 234,214,000 203,167,000 187,096,000 190,382,000 220,607,000 188,148,000 193,913,000 184,445,000 207,349,000 167,470,000 162,234,000 169,400,000 205,400,000 474,800,000 477,900,000 470,300,000 540,700,000 491,200,000 485,200,000 335,900,000 330,100,000 336,700,000 393,800,000 377,500,000 452,500,000 480,200,000 595,200,000 572,500,000 613,400,000 551,500,000 580,600,000 510,600,000 499,300,000 484,900,000 523,000,000 456,800,000 461,800,000 449,200,000 522,900,000 477,300,000 483,600,000 426,000,000 448,700,000 412,700,000 376,000,000 348,200,000 
        assets held for sale
      12,216,000 15,359,000 17,022,000 13,197,000 14,159,000 4,483,000 4,739,000 7,270,000 6,466,000 3,936,000                5,116,000 5,130,000 4,330,000     1,373,000 1,373,000 1,824,000 2,016,000 5,005,000 15,570,000 17,593,000 17,497,000            1,500,000 1,500,000 10,000,000 10,000,000 31,400,000 31,400,000 23,700,000 23,700,000                            
        prepaid insurance
      2,178,000 8,003,000 11,193,000   3,955,000 7,192,000 11,248,000 1,790,000 3,907,000 7,150,000 11,840,000 1,999,000 4,249,000 7,766,000 11,283,000 4,184,000 7,977,000 11,903,000                                                                    
        other current assets
      25,905,000 27,044,000 14,792,000 21,919,000 27,639,000 29,269,000 23,612,000 19,558,000 15,499,000 12,314,000 12,826,000 12,918,000 15,907,000 17,156,000 14,252,000 12,215,000 15,274,000 9,064,000 12,312,000  12,996,000 19,089,000                                                                 
        total current assets
      203,157,000 207,717,000 227,308,000 227,497,000 264,738,000 259,022,000 231,036,000 212,839,000 231,998,000 258,147,000 262,111,000 256,254,000 260,407,000 229,279,000 218,576,000 206,652,000 192,383,000 189,313,000 192,781,000 188,146,000 198,604,000 190,703,000 188,927,000 200,668,000 180,310,000 175,581,000 164,031,000 164,174,000 151,466,000 152,386,000 162,289,000 176,988,000 164,248,000 343,959,000 330,895,000 381,732,000 384,249,000 320,964,000 315,766,000 361,434,000 411,293,000 359,604,000 355,014,000 465,713,000 450,443,000 406,342,000 403,237,000 461,290,000 454,955,000 392,640,000 406,862,000 486,800,000 509,100,000 1,274,100,000 1,341,400,000 1,375,100,000 1,331,000,000 1,311,400,000 1,283,400,000 1,016,700,000 968,300,000 967,600,000 969,100,000 925,000,000 1,001,800,000 1,141,200,000 1,338,600,000 1,358,900,000 1,428,700,000 1,434,800,000 1,365,800,000 1,232,100,000 1,085,700,000 1,153,800,000 1,118,600,000 1,010,800,000 1,030,400,000 1,073,700,000 1,041,900,000 979,600,000 1,009,600,000 996,800,000 904,600,000 845,600,000 814,200,000  
        property, plant and equipment
      309,914,000 274,112,000 256,762,000 263,893,000 259,457,000 244,712,000 241,153,000 238,906,000 223,902,000 236,836,000 224,302,000 219,772,000 217,952,000 213,435,000 210,470,000 196,463,000 189,369,000 175,553,000 169,135,000 172,417,000 156,598,000 143,208,000 139,609,000 138,061,000 129,585,000 122,327,000 125,842,000 124,554,000 126,055,000 123,632,000 119,811,000 120,068,000 116,336,000 132,126,000 132,158,000 131,049,000 124,626,000 132,290,000 132,345,000 132,539,000 151,767,000 154,020,000 156,551,000 159,644,000 252,039,000 254,362,000 245,858,000 219,256,000 193,864,000 185,626,000 184,062,000 183,000,000 193,500,000 274,700,000 253,300,000 254,300,000 257,000,000 270,900,000 268,200,000 277,000,000 288,300,000 323,900,000 340,300,000 345,200,000 346,500,000 358,900,000 381,400,000 385,300,000 378,300,000 374,200,000 361,500,000 371,500,000 372,100,000 371,400,000 360,500,000 364,500,000 362,400,000 399,400,000 409,600,000 404,500,000 408,100,000 415,800,000 399,200,000 402,600,000 405,900,000 412,600,000 
        intangibles
      4,574,000 4,901,000 5,068,000 5,313,000 5,475,000 5,633,000 5,764,000 5,880,000 6,006,000 25,759,000 26,401,000 27,328,000 28,055,000 29,001,000 29,868,000 30,927,000 32,534,000 33,437,000 34,348,000 35,330,000 35,599,000 36,333,000 37,125,000 37,902,000 38,273,000 38,987,000 39,869,000 40,516,000 41,342,000 42,056,000 42,870,000 43,554,000 44,036,000                                                      
        mining supplies inventory
      42,815,000 34,548,000 33,674,000 31,177,000                                                                                   
        deferred income taxes
      13,861,000 21,126,000 18,404,000 16,984,000 14,641,000 17,389,000 15,018,000 15,113,000 15,081,000 4,206,000 4,746,000 3,701,000 6,122,000 11,299,000 10,808,000 14,303,000 12,563,000 14,784,000 17,973,000 17,550,000 28,513,000 18,345,000 18,573,000 12,338,000 7,361,000 6,241,000 6,026,000  548,000 2,663,000 4,465,000 5,962,000 7,145,000 23,839,000 26,333,000 28,380,000 23,812,000 29,997,000 33,588,000 42,013,000 23,024,000 19,705,000 17,562,000 18,566,000 11,486,000 12,740,000 10,721,000 14,452,000 14,428,000 13,701,000 10,604,000 15,300,000 23,900,000 22,500,000 28,800,000 30,700,000 19,500,000 16,300,000 14,800,000 23,000,000 21,300,000 23,400,000 30,200,000 31,800,000 34,100,000 38,200,000 46,900,000 55,000,000 48,400,000 51,100,000     30,100,000 29,400,000 35,800,000 42,000,000 37,800,000 33,300,000 33,200,000 33,000,000 38,300,000 36,600,000 33,600,000 38,100,000 
        investments in unconsolidated subsidiaries
      15,513,000 18,560,000 16,093,000 16,009,000 14,137,000 16,682,000 15,371,000 13,753,000 12,371,000 11,461,000 11,064,000 13,945,000  9,853,000 15,379,000 18,452,000 19,312,000 20,927,000 29,763,000  25,545,000 25,337,000 27,384,000  23,100,000 22,373,000 23,268,000  19,999,000 18,444,000 18,679,000  27,281,000 27,254,000 35,906,000                                                    
        operating lease right-of-use assets
      8,996,000 8,469,000 8,869,000 9,267,000 9,661,000 7,744,000 8,080,000 7,876,000 8,667,000 7,422,000 6,121,000 6,221,000 6,419,000 7,912,000 8,250,000 8,583,000 9,235,000 9,594,000 9,959,000 10,324,000 10,448,000 10,748,000 11,081,000 11,398,000 11,721,000 12,095,000 12,479,000                                                            
        equity securities
      18,194,000 18,109,000 17,769,000 17,819,000 18,663,000                                                                                  
        equity method investment in eiger resources
      33,685,000 19,066,000                                                                                     
        other non-current assets
      34,947,000 31,025,000 28,411,000 26,527,000 25,768,000 46,224,000 43,636,000 43,631,000 41,683,000 41,278,000 41,511,000 38,604,000 40,312,000 50,766,000 47,019,000 51,930,000 46,085,000 45,215,000 43,243,000 40,984,000 39,108,000 36,625,000 31,794,000 28,189,000 29,781,000 24,632,000 25,083,000 24,412,000 23,637,000 23,310,000 22,507,000 23,063,000 22,740,000 26,169,000 26,409,000 26,557,000 71,299,000 64,985,000 62,704,000 56,326,000 59,770,000 60,961,000 64,422,000 62,283,000 69,661,000 70,160,000 71,985,000 69,725,000 64,680,000 54,185,000 54,093,000 36,700,000 40,000,000 95,200,000 94,100,000 110,600,000 108,700,000 109,300,000 111,000,000 114,500,000 117,400,000 121,900,000 122,400,000 117,600,000 113,000,000 99,800,000 98,900,000 90,700,000 88,500,000 88,700,000 111,200,000 116,200,000 118,300,000 119,100,000 127,800,000 135,200,000 134,100,000 110,800,000 102,700,000 106,600,000 111,200,000 110,600,000 92,700,000 95,800,000 97,500,000 97,700,000 
        total assets
      685,656,000 637,633,000 631,312,000 634,187,000 631,687,000 597,406,000 560,058,000 537,998,000 539,708,000 580,903,000 571,510,000 562,124,000 568,072,000 560,204,000 547,344,000 513,007,000 488,918,000 474,039,000 479,229,000 476,179,000 465,902,000 442,954,000 435,920,000 444,773,000 412,770,000 399,180,000 393,787,000 376,991,000 366,546,000 366,018,000 374,176,000 389,552,000 384,949,000 621,260,000 620,291,000 668,021,000 664,110,000 609,523,000 606,514,000 655,408,000 702,717,000 651,399,000 653,637,000 770,520,000 829,160,000 788,793,000 780,000,000 809,956,000 778,089,000 698,117,000 713,728,000 776,300,000 822,000,000 1,704,800,000 1,749,800,000 1,801,400,000 1,757,500,000 1,754,400,000 1,727,200,000 1,482,200,000 1,450,100,000 1,488,700,000 1,517,600,000 1,469,500,000 1,550,000,000 1,687,900,000 2,337,000,000 2,367,800,000 2,427,500,000 2,428,200,000 2,351,500,000 2,232,100,000 2,088,000,000 2,156,300,000 2,116,500,000 2,020,200,000 2,036,100,000 2,094,000,000 2,066,100,000 2,002,800,000 2,043,500,000 2,038,600,000 1,909,600,000 1,857,100,000 1,833,300,000  
        liabilities and equity
                                                                                            
        accounts payable
      19,872,000 20,447,000 14,935,000 14,564,000 17,721,000 16,232,000 14,226,000 12,377,000 16,702,000 24,589,000 12,898,000 10,610,000 11,952,000 11,371,000 16,490,000 11,037,000 13,904,000 9,889,000 7,797,000 5,522,000 13,603,000 9,822,000 8,383,000 9,374,000 9,004,000 7,703,000 8,224,000 7,746,000 9,655,000 9,120,000 8,174,000 7,575,000 8,466,000 104,794,000 87,119,000 128,248,000 157,253,000 100,878,000 90,247,000 100,300,000 161,040,000 116,246,000 101,011,000 133,668,000 149,343,000 99,319,000 103,642,000 133,016,000 141,919,000 90,334,000 90,576,000 127,500,000 134,400,000 396,600,000 412,000,000 412,500,000 474,800,000 414,000,000 422,800,000 305,700,000 268,700,000 271,700,000 279,600,000 216,500,000 265,700,000 376,400,000 500,300,000 460,700,000 498,900,000 505,200,000 463,500,000 390,900,000 391,400,000 432,100,000 425,400,000 367,300,000 377,500,000 394,300,000 383,000,000 383,700,000 409,900,000 399,800,000 327,900,000 336,600,000 332,900,000 295,800,000 
        accounts payable to affiliates
      648,000 924,000 8,000 1,817,000 1,826,000 982,000 1,391,000 691,000 904,000 1,268,000 158,000 868,000 1,362,000 699,000 885,000 909,000 562,000 517,000 440,000 125,000 686,000 1,907,000 157,000 577,000 37,000 344,000 637,000 1,653,000 383,000 4,609,000 237,000 1,925,000 3,228,000                                                      
        current maturities of long-term debt
      8,959,000 4,644,000 4,631,000 4,634,000 4,179,000 4,183,000 4,369,000 4,498,000 3,953,000 3,579,000 3,675,000 2,943,000 3,649,000 2,955,000 2,929,000 2,965,000 2,503,000 1,168,000 2,068,000 2,112,000 960,000 941,000 933,000 795,000 394,000 499,000 573,000 654,000 647,000 1,037,000 1,081,000 1,125,000 1,168,000                                                      
        asset retirement obligations
      6,741,000 9,595,000 9,646,000 9,696,000 9,747,000 14,259,000 13,095,000 13,105,000 13,114,000 8,102,000 2,497,000 2,497,000 1,746,000 1,820,000 1,820,000 1,820,000 1,844,000 1,844,000 1,844,000 1,844,000 2,285,000 2,285,000 2,285,000 2,285,000 1,826,000 1,826,000 1,826,000 1,826,000 3,092,000 3,092,000 3,092,000 3,092,000 3,555,000 39,153,000 38,823,000 38,262,000 41,965,000 41,588,000 41,286,000 39,780,000             34,600,000                                  
        accrued payroll
      9,786,000 17,810,000 14,177,000 11,913,000 22,663,000 18,782,000 12,927,000 9,069,000 17,317,000 13,451,000 9,849,000 7,922,000 18,105,000 16,640,000 11,281,000 8,040,000 13,011,000 9,200,000 7,309,000 14,430,000 10,565,000 11,405,000 6,519,000 19,583,000 20,243,000 17,393,000 13,515,000 19,853,000 13,241,000 9,627,000 6,010,000 17,204,000 12,400,000 20,332,000 14,033,000 32,925,000 24,292,000 18,513,000 13,057,000 40,854,000 34,336,000 29,484,000 24,135,000 23,567,000 19,136,000 14,837,000 10,351,000 29,030,000 22,469,000 18,378,000 13,590,000 24,200,000 18,000,000 43,100,000 32,000,000 61,700,000 48,700,000 42,100,000 31,500,000 43,900,000 35,700,000 44,300,000 23,800,000 21,900,000 18,800,000 34,200,000 35,500,000 37,600,000 33,000,000 63,800,000 42,600,000 36,300,000 29,600,000 45,100,000 37,400,000 33,800,000 26,900,000 45,600,000 38,300,000 32,200,000 27,100,000 42,800,000 35,300,000 30,100,000  44,500,000 
        excess funding liability
      5,450,000 5,450,000 5,450,000 14,490,000                                                                                   
        other current liabilities
      10,018,000 9,022,000 9,347,000 9,445,000 8,752,000 9,452,000 7,475,000 6,265,000 7,118,000 8,582,000 7,312,000 7,128,000 6,623,000 9,150,000 8,430,000 8,664,000 9,086,000 8,807,000 8,461,000 8,224,000 6,786,000 6,675,000 6,627,000 8,887,000 7,806,000 7,937,000 7,330,000 6,516,000 7,168,000 6,436,000 7,245,000 8,055,000 10,964,000 30,537,000 26,634,000 31,141,000 30,560,000 27,395,000 25,373,000 28,112,000 45,270,000 34,248,000 36,083,000 36,964,000 41,325,000 37,868,000 32,836,000 35,877,000 40,418,000 30,510,000 27,366,000 33,200,000 40,800,000 141,500,000 139,900,000 160,700,000 157,000,000 155,600,000 154,000,000 91,100,000 87,400,000 89,100,000 123,600,000 117,200,000 126,200,000 151,700,000 136,700,000 151,000,000 189,300,000 202,000,000 192,300,000 177,700,000 171,200,000 217,200,000 169,300,000 161,100,000 161,900,000 176,000,000 167,200,000 154,600,000 162,700,000 158,700,000 179,300,000 169,700,000 200,400,000 151,600,000 
        total current liabilities
      61,474,000 67,892,000 58,194,000 66,559,000 64,888,000 68,923,000 81,826,000 63,935,000 69,986,000 60,870,000 37,511,000 34,012,000 44,270,000 43,969,000 43,638,000 36,424,000 40,910,000 40,425,000 45,919,000 52,257,000 36,578,000 39,261,000 38,107,000 61,966,000 52,775,000 53,167,000 49,570,000 42,248,000 44,186,000 45,921,000 40,839,000 53,976,000 43,223,000 186,049,000 167,204,000 221,828,000 229,506,000 161,684,000 140,797,000 191,746,000 255,999,000 192,803,000 185,217,000 254,681,000 287,495,000 234,425,000 202,061,000 238,119,000 250,468,000 173,455,000 181,251,000 227,200,000 243,800,000 690,300,000 870,500,000 891,200,000 842,600,000 719,500,000 661,900,000 522,800,000 473,000,000 479,300,000 542,500,000 486,300,000 582,200,000 675,300,000 847,300,000 816,400,000 874,100,000 856,500,000 799,400,000 695,400,000 653,700,000 751,000,000 746,900,000 665,500,000 683,400,000 704,700,000 699,000,000 647,700,000 678,500,000 672,000,000 628,200,000 586,900,000 594,100,000  
        long-term debt
      17,443,000 25,518,000 25,875,000 26,193,000 25,335,000 28,818,000 29,027,000 28,377,000 22,003,000 18,955,000 20,054,000 17,434,000 16,019,000 15,322,000 15,498,000 22,573,000 14,501,000 21,805,000 24,292,000 24,353,000 22,182,000 22,482,000 22,649,000 17,148,000 7,284,000 7,503,000 7,448,000 6,367,000 6,849,000 14,946,000 34,687,000 42,021,000 57,573,000                                                      
        long-term revolving credit agreements
      100,000,000 50,000,000 65,000,000 65,000,000  37,221,000                                                                                 
        operating lease liabilities
      7,451,000 7,687,000 8,152,000 8,603,000 9,042,000 7,652,000 8,039,000 7,962,000 8,782,000 8,201,000 7,048,000 7,278,000 7,528,000 8,944,000 9,214,000 9,478,000 10,109,000 10,479,000 10,842,000 11,196,000 11,494,000 11,782,000 12,117,000 12,448,000 12,669,000 12,990,000 13,305,000                                                            
        retirement benefit plans
      4,447,000                                                                                      
        other long-term liabilities
      20,158,000 16,944,000 15,975,000 13,740,000 12,114,000 8,486,000 7,598,000 6,707,000 6,120,000 6,069,000 8,552,000 7,813,000 8,500,000 7,700,000 7,175,000 7,343,000 11,449,000 12,464,000 12,600,000 12,060,000 12,405,000 8,509,000 7,682,000 8,100,000 6,696,000 6,856,000 6,720,000 15,581,000 15,202,000 13,975,000 13,629,000 12,336,000 11,113,000 51,794,000 50,642,000 53,072,000 53,446,000 51,061,000 51,856,000 52,585,000 53,160,000 52,112,000 52,162,000 64,919,000 66,632,000 66,013,000 60,122,000 59,428,000 55,025,000 51,894,000 50,555,000 51,600,000 45,600,000 114,200,000 112,300,000 110,400,000 119,100,000 117,900,000 115,900,000 123,200,000 127,500,000 136,200,000 142,000,000 139,600,000 148,100,000 154,300,000 141,700,000 144,800,000 157,400,000 165,900,000                 
        total liabilities
      248,545,000 211,231,000 218,192,000 225,070,000 226,740,000 200,096,000 175,968,000 156,385,000 157,368,000 152,458,000 138,112,000 130,438,000 141,106,000 144,783,000 144,741,000 148,513,000 147,999,000 158,312,000 169,860,000 175,555,000 159,413,000 143,683,000 142,083,000 155,381,000 129,515,000 127,030,000 129,520,000 126,287,000 126,345,000 135,046,000 149,294,000 170,104,000 177,886,000 390,300,000 395,765,000 447,728,000 467,802,000 410,551,000 404,495,000 454,270,000 517,973,000 459,305,000 450,687,000 559,046,000 559,918,000 514,006,000 490,457,000 512,176,000 502,368,000 430,091,000 433,235,000 494,900,000 530,900,000 1,088,100,000 1,139,100,000 1,224,400,000 1,209,700,000 1,213,200,000 1,210,500,000 1,094,900,000 1,061,600,000 1,091,600,000 1,148,200,000 1,097,300,000 1,209,100,000 1,331,000,000 1,475,900,000 1,457,100,000 1,529,900,000 1,536,100,000                 
        stockholders' equity
                                                                                            
        common stock:
                                                                                            
        class a, par value 1 per share, 5,977,652 shares outstanding
      5,978,000                                                                                      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,562,953 shares outstanding
      1,563,000                                                                                      
        capital in excess of par value
      43,200,000 40,016,000 38,223,000 35,718,000 34,340,000 31,621,000 30,451,000 29,073,000 28,672,000 25,415,000 24,906,000 24,109,000 23,706,000 23,235,000 19,634,000 17,309,000 14,542,000 12,928,000 11,818,000 10,895,000 9,381,000 8,942,000 8,318,000 8,911,000 9,829,000 7,734,000 6,573,000 7,042,000 6,341,000 5,269,000 4,537,000 4,447,000 2,219,000      712,000         941,000 367,000 4,185,000 20,035,000 24,500,000 24,900,000 24,300,000 23,200,000 22,700,000 24,800,000 24,100,000 23,400,000 17,500,000 16,700,000 16,100,000 14,600,000 14,400,000 14,600,000 14,400,000 14,900,000 15,000,000 14,600,000 14,100,000 14,000,000 13,500,000 13,000,000 12,500,000 10,300,000 9,600,000 8,700,000 7,200,000 7,000,000 6,900,000 6,800,000 6,000,000 5,700,000 5,700,000 5,700,000 5,300,000 
        retained earnings
      388,063,000 388,652,000 377,280,000 375,899,000 373,363,000 367,814,000 355,786,000 354,667,000 355,873,000 404,478,000 409,946,000 409,059,000 404,924,000 392,666,000 383,574,000 347,915,000 330,373,000 306,950,000 301,857,000 294,270,000 301,045,000 294,378,000 289,679,000 284,852,000 279,801,000 270,865,000 264,217,000 250,352,000 239,817,000 231,761,000 226,513,000 216,490,000 207,447,000 248,239,000 242,379,000 239,441,000 214,666,000 217,728,000 218,743,000 217,745,000 200,853,000 206,400,000 216,927,000 224,428,000 274,297,000 279,922,000 294,183,000 301,227,000 327,746,000 318,885,000 315,770,000 313,600,000 321,300,000 657,600,000 640,400,000 619,700,000 569,800,000 548,500,000 533,800,000 432,200,000 420,700,000 413,300,000 375,000,000 383,200,000 385,900,000 399,300,000 829,600,000 851,200,000 853,100,000 855,600,000 808,100,000 791,100,000 785,300,000 792,500,000 726,500,000 711,600,000 710,900,000 729,600,000 701,100,000 691,300,000 683,800,000 682,300,000 653,500,000 643,800,000 640,600,000 648,200,000 
        accumulated other comprehensive loss
      -1,693,000 -9,726,000 -9,835,000 -9,943,000 -10,052,000 -9,423,000 -9,501,000 -9,578,000 -9,654,000 -8,954,000 -8,974,000 -8,992,000 -9,013,000 -7,822,000 -7,940,000 -8,058,000 -11,170,000 -11,313,000 -11,456,000 -11,599,000 -10,982,000 -11,081,000 -11,182,000 -11,337,000 -13,369,000 -13,439,000 -13,510,000 -13,611,000 -12,899,000 -13,002,000 -13,107,000 -8,341,000 -9,449,000 -24,115,000 -24,687,000 -25,927,000 -25,134,000 -25,569,000 -24,315,000 -23,444,000 -22,958,000 -21,286,000 -21,125,000  -12,450,000 -12,762,000 -12,439,000  -60,330,000 -63,081,000 -63,650,000  -63,500,000 -74,400,000 -62,100,000                                
        total stockholders' equity
      437,111,000 426,402,000 413,120,000 409,117,000  397,310,000 384,090,000 381,613,000  428,445,000 433,398,000 431,686,000  415,421,000 402,603,000 364,494,000 340,919,000 315,727,000 309,369,000  306,489,000 299,271,000 293,837,000  283,255,000 272,150,000 264,267,000  240,201,000 230,972,000 224,882,000  207,063,000 230,960,000 224,526,000  196,308,000 198,972,000 202,019,000  184,744,000 192,094,000 202,950,000  269,242,000 274,787,000 289,543,000  275,721,000 268,026,000 280,493,000  291,100,000 615,900,000 609,900,000  547,100,000 540,500,000 515,900,000                            
        total liabilities and equity
      685,656,000 637,633,000 631,312,000 634,187,000 631,687,000 597,406,000 560,058,000 537,998,000 539,708,000 580,903,000 571,510,000 562,124,000 568,072,000 560,204,000 547,344,000 513,007,000 488,918,000 474,039,000 479,229,000 476,179,000 465,902,000 442,954,000 435,920,000 444,773,000 412,770,000 399,180,000 393,787,000 376,991,000 366,546,000 366,018,000 374,176,000 389,552,000 384,949,000 621,260,000 620,291,000 668,021,000 664,110,000 609,523,000 606,514,000 655,408,000 702,717,000 651,399,000 653,637,000 770,520,000 829,160,000 788,793,000 780,000,000 809,956,000 778,089,000 698,117,000 713,728,000 776,300,000 822,000,000 1,704,800,000 1,749,800,000 1,801,400,000 1,757,500,000 1,754,400,000 1,727,200,000 1,482,200,000 1,450,100,000 1,488,700,000 1,517,600,000 1,469,500,000 1,550,000,000                      
        deposits with vendors
        16,293,000 14,489,000                                                                                   
        pension and other postretirement obligations
       4,483,000 4,614,000 4,735,000 4,787,000 4,710,000 4,904,000 5,059,000 5,183,000 4,049,000 4,307,000 4,778,000 5,082,000 4,943,000 5,422,000 6,001,000 7,361,000 7,847,000 8,315,000 8,838,000 7,430,000 7,883,000 8,322,000 8,807,000 9,365,000 9,711,000 10,067,000 10,429,000 10,550,000 10,917,000 11,293,000 11,827,000 12,924,000 13,386,000 13,783,000 14,271,000 12,361,000 12,747,000 13,088,000 10,046,000 9,711,000 9,831,000 10,498,000 10,616,000 7,312,000 7,355,000 7,409,000 7,648,000 15,466,000 23,166,000 23,735,000 24,400,000 24,500,000 72,200,000 75,700,000 81,000,000 56,200,000 67,300,000 71,200,000 81,200,000 88,700,000 98,500,000                         
        class a, par value 1 per share, 5,896,802 shares outstanding
       5,896,000                                                                                     
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,563,153 shares outstanding
       1,564,000                                                                                     
        equity method investment in eiger, llc
        18,954,000 19,701,000 19,147,000                                                                                  
        class a, par value 1 per share, 5,888,400 shares outstanding
        5,888,000                                                                                    
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,563,253 shares outstanding
        1,564,000                                                                                    
        class a, par value 1 per share, 5,876,777 shares outstanding
         5,877,000                                                                                   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,353 shares outstanding
         1,566,000                                                                                   
        current assets
                                                                                            
        current liabilities
                                                                                            
        revolving credit agreements
            27,500,000 17,000,000 10,000,000         9,000,000 18,000,000 20,000,000  5,000,000 11,000,000 7,000,000  4,000,000 4,000,000 4,000,000 10,000,000 12,000,000 15,000,000 15,000,000                                                       
        long-term revolving credit agreement
          70,000,000                                                                                  
        liability for uncertain tax positions
          794,000 5,795,000 5,795,000 5,795,000 5,795,000 8,552,000 9,004,000 9,004,000 9,329,000 9,280,000 10,113,000 10,113,000 9,413,000 9,413,000 9,413,000 9,413,000                                                                   
        stockholders’ equity
                                                                                            
        class a, par value 1 per share, 5,730,470 shares outstanding
          5,730,000                                                                                  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,359 shares outstanding
          1,566,000                                                                                  
        total stockholders’ equity
          404,947,000    382,340,000    426,966,000       300,624,000    289,392,000    250,704,000    219,448,000    220,293,000    201,138,000    211,474,000    297,780,000    281,400,000    576,200,000    386,800,000 388,100,000 396,600,000 369,100,000 371,800,000 340,700,000                      
        cash held by 1031 exchange facilitator
           5,310,000 6,721,000                                                                                
        business interruption insurance receivable
           13,612,000                                                                                 
        deferred revenue
           723,000 843,000 930,000 878,000 1,299,000 1,122,000 2,044,000 833,000 1,334,000 1,803,000 2,989,000     1,693,000 1,226,000 2,203,000                              1,600,000 9,400,000 11,700,000 11,200,000 13,700,000 10,500,000 12,600,000 10,200,000 11,900,000 12,500,000 12,900,000 12,500,000 17,900,000 17,700,000 21,800,000 19,600,000 16,700,000 18,400,000                 
        federal income tax payable
           4,310,000                                                                                 
        class a, par value 1 per share, 5,731,447 shares outstanding
           5,732,000                                                                                 
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,519 shares outstanding
           1,566,000                                                                                 
        class a, par value 1 per share, 5,787,521 shares outstanding
            5,788,000                                                                                
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,685 shares outstanding
            1,566,000 1,566,000                                                                               
        federal income tax receivable
             845,000 845,000 5,864,000 4,272,000 15,098,000 15,687,000 23,046,000   8,959,000 9,334,000                                                                     
        class a, par value 1 per share, 5,884,740 shares outstanding
             5,885,000                                                                               
        class a, par value 1 per share, 5,882,845 shares outstanding
              5,883,000                                                                              
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,819 shares outstanding
              1,566,000 1,566,000                                                                             
        class a, par value 1 per share, 5,939,643 shares outstanding
               5,940,000                                                                             
        class a, par value 1 per share, 5,954,538 shares outstanding
                5,954,000                                                                            
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,565,929 shares outstanding
                1,566,000 1,566,000                                                                           
        class a, par value 1 per share, 5,944,585 shares outstanding
                 5,944,000                                                                           
        investment in unconsolidated subsidiaries
                  14,927,000       28,978,000    24,611,000    20,091,000    16,335,000    31,054,000                                                   
        class a, par value 1 per share, 5,782,944 shares outstanding
                  5,783,000                                                                          
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,566,129 shares outstanding
                  1,566,000                                                                          
        investment in private company equity units
                   19,958,000 17,782,000                                                                        
        class a, par value 1 per share, 5,775,910 shares outstanding
                   5,776,000                                                                         
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,566,373 shares outstanding
                   1,566,000 1,566,000                                                                        
        refundable federal income taxes
                    3,919,000 12,537,000   14,518,000 17,615,000 25,379,000 15,286,000 14,638,000                                                                
        class a, par value 1 per share, 5,768,580 shares outstanding
                    5,769,000                                                                        
        class a, par value 1 per share, 5,761,856 shares outstanding
                     5,762,000                                                                       
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,566,413 shares outstanding
                     1,566,000                                                                       
        class a, par value 1 per share, 5,607,149 shares outstanding
                      5,607,000                                                                      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,566,643 shares outstanding
                      1,567,000 1,567,000 1,567,000                                                                    
        class a, par value 1 per share, 5,595,368 shares outstanding
                       5,595,000                                                                     
        class a, par value 1 per share, 5,583,099 shares outstanding
                        5,583,000                                                                    
        prepaid expenses and other
                         10,872,000   17,068,000 15,456,000 12,515,000 14,891,000 18,898,000 14,562,000 10,762,000 12,703,000 13,074,000 7,986,000 6,323,000 22,323,000 20,476,000 16,859,000 28,696,000 21,925,000 19,680,000 12,317,000 21,318,000 25,977,000 26,918,000 14,743,000 25,774,000 23,195,000 21,498,000 13,578,000 15,644,000 16,111,000 19,272,000 11,400,000 14,900,000 46,800,000 64,400,000 39,600,000 38,700,000 41,100,000 44,200,000 72,900,000 66,300,000 35,000,000 43,900,000 52,200,000 64,500,000 65,300,000 62,100,000 69,300,000 68,600,000 38,300,000 79,300,000 77,200,000 75,100,000 70,700,000 53,800,000 56,700,000 62,000,000 50,000,000 44,800,000 41,800,000 46,100,000 35,900,000 55,400,000 62,000,000 64,500,000 36,900,000 
        deferred compensation
                             13,465,000 13,465,000 13,465,000 13,465,000 12,939,000 12,939,000 12,939,000 12,939,000 12,939,000 13,571,000                                                      
        class a, par value 1 per share, 5,489,615 shares outstanding
                         5,490,000                                                                   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,210 shares outstanding
                         1,568,000                                                                   
        class a, par value 1 per share, 5,477,225 shares outstanding
                          5,477,000                                                                  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,350 shares outstanding
                          1,568,000                                                                  
        class a, par value 1 per share, 5,463,761 shares outstanding
                           5,463,000                                                                 
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,550 shares outstanding
                           1,569,000                                                                 
        class a, par value 1 per share, 5,452,830 shares outstanding
                            5,453,000                                                                
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,554 shares outstanding
                            1,569,000                                                                
        trade accounts receivable, net of allowances of 0 and 1,523 in 2019 and 2018, respectively
                             15,444,000                                                               
        deferred costs
                             3,944,000  3,185,000 3,215,000 3,244,000 3,499,000 3,527,000 3,555,000 3,582,000 3,163,000 10,598,000 10,311,000 10,037,000                                                   
        class a, par value 1 per share, 5,397,458 shares outstanding
                             5,397,000                                                               
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,670 shares outstanding
                             1,569,000                                                               
        class a, par value 1 per share, 5,425,640 shares outstanding
                              5,425,000                                                              
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,680 shares outstanding
                              1,569,000                                                              
        class a, par value 1 per share, 5,421,134 shares outstanding
                               5,421,000                                                             
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,780 shares outstanding
                               1,569,000                                                             
        class a, par value 1 per share, 5,417,906 shares outstanding
                                5,418,000                                                            
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,568,810 shares outstanding
                                1,569,000 1,569,000                                                           
        trade accounts receivable, net of allowances of 1,523 in 2018 and 2017
                                 20,817,000                                                           
        class a, par value 1 per share, 5,352,590 shares outstanding
                                 5,352,000                                                           
        class a, par value 1 per share, 5,373,404 shares outstanding
                                  5,373,000                                                          
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,569,250 shares outstanding
                                  1,569,000                                                          
        accounts receivable
                                   17,908,000 14,004,000 17,468,000 9,070,000 85,025,000 79,718,000 117,463,000 97,613,000 77,173,000 73,851,000 111,020,000 118,097,000 88,295,000 92,007,000 123,466,000 97,639,000 85,001,000 74,788,000 120,789,000 107,630,000 81,271,000 90,240,000 121,200,000 107,700,000 416,800,000 445,400,000 464,500,000 483,100,000 437,600,000 465,700,000 314,900,000 317,300,000 315,000,000 313,600,000 284,700,000 294,900,000 419,200,000 462,900,000 474,600,000 476,000,000 512,500,000 465,800,000 390,500,000 394,100,000 401,500,000 406,100,000 355,900,000 342,000,000 366,000,000 351,400,000 343,800,000 333,900,000 351,500,000 330,000,000 289,500,000 290,200,000  
        class a, par value 1 per share, 5,374,722 shares outstanding
                                   5,375,000                                                         
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,569,422 shares outstanding
                                   1,569,000                                                         
        class a, par value 1 per share, 5,369,326 shares outstanding
                                    5,369,000                                                        
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,569,746 shares outstanding
                                    1,570,000                                                        
        current assets of discontinued operations
                                                                   1,300,000                         
        long-term assets of discontinued operations
                                                                                            
        current liabilities of discontinued operations
                                                                   1,900,000                         
        long-term liabilities of discontinued operations
                                                                                            
        class a, par value 1 per share, 5,282,106 shares outstanding
                                     5,282,000                                                       
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,570,146 shares outstanding
                                     1,570,000                                                       
        accrued income taxes
                                      3,442,000       1,935,000    4,015,000    8,877,000                                       
        class a, par value 1 per share, 5,276,050 shares outstanding
                                      5,276,000                                                      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,570,148 shares outstanding
                                      1,570,000                                                      
        accounts receivable from unconsolidated subsidiaries
                                       11,270,000 13,469,000 7,404,000                                                   
        goodwill
                                       6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000 6,253,000     3,973,000 3,973,000 6,399,000 6,400,000 7,500,000              439,400,000 445,200,000 444,200,000 441,900,000 441,300,000 439,700,000 438,500,000 437,800,000 435,900,000 435,200,000 434,100,000 434,200,000 435,000,000 434,400,000 436,100,000 437,000,000 434,100,000 433,200,000 434,900,000 435,000,000 
        other intangibles
                                       51,062,000 52,026,000 52,959,000 53,871,000 55,034,000 55,858,000 56,843,000 57,650,000 58,786,000 59,737,000 60,821,000                                           
        revolving credit agreements of subsidiaries - not guaranteed by the parent company
                                       22,276,000 30,978,000  5,250,000 6,158,000 4,170,000  13,858,000 11,340,000 22,512,000  69,805,000 74,524,000 47,364,000  37,812,000 27,264,000 42,754,000  42,000,000                                  
        current maturities of long-term debt of subsidiaries - not guaranteed by the parent company
                                       1,212,000 1,757,000  1,532,000 1,523,000 1,513,000  1,495,000 1,485,000 1,476,000  7,886,000 7,877,000 7,868,000  7,850,000 6,969,000 6,965,000  7,000,000                                  
        accrued cooperative advertising
                                       6,898,000 6,683,000 15,056,000 10,619,000 7,217,000 6,437,000 10,676,000                                               
        long-term debt of subsidiaries - not guaranteed by the parent company
                                       99,918,000 125,313,000  130,524,000 143,471,000 157,468,000  158,650,000 166,239,000 164,935,000  138,958,000 147,257,000 168,069,000  129,123,000 129,687,000 123,839,000  158,400,000                                  
        class a, par value 1 per share, 5,266,268 shares outstanding
                                       5,266,000                                                     
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,570,448 shares outstanding
                                       1,570,000                                                     
        class a, par value 1 per share, 5,263,307 shares outstanding
                                        5,263,000                                                    
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,570,515 shares outstanding
                                        1,571,000                                                    
        revolving credit agreements of subsidiaries — not guaranteed by the parent company
                                         12,714,000    8,365,000    55,000,000    23,460,000    35,300,000                                   
        current maturities of long-term debt of subsidiaries — not guaranteed by the parent company
                                         1,744,000    1,504,000    1,467,000    7,859,000    7,000,000                                   
        long-term debt of subsidiaries — not guaranteed by the parent company
                                         120,295,000    160,113,000    191,431,000    152,431,000    135,400,000                                   
        class a, par value 1 per share, 5,207,955 shares outstanding
                                         5,208,000                                                   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,570,915 shares outstanding
                                         1,571,000                                                   
        class a, par value 1 per share, 5,205,293 shares outstanding
                                          5,205,000                                                  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,571,215 shares outstanding
                                          1,571,000                                                  
        class a, par value 1 per share, 5,240,777 shares outstanding
                                           5,241,000                                                 
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,571,518 shares outstanding
                                           1,572,000                                                 
        class a, par value 1 per share, 5,307,743 shares outstanding
                                            5,308,000                                                
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,571,528 shares outstanding
                                            1,571,000                                                
        class a, par value 1 per share, 5,265,446 shares outstanding
                                             5,265,000                                               
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,571,727 shares outstanding
                                             1,572,000                                               
        mine closing reserves
                                              40,453,000 38,320,000 37,875,000 37,399,000 36,217,000 35,930,000 29,878,000 29,764,000 29,212,000 28,928,000 29,223,000 29,000,000                                   
        class a, par value 1 per share, 5,276,963 shares outstanding
                                              5,277,000                                              
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,572,027 shares outstanding
                                              1,572,000                                              
        class a, par value 1 per share, 5,407,112 shares outstanding
                                               5,407,000                                             
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,572,627 shares outstanding
                                               1,573,000                                             
        class a, par value 1 per share, 5,574,814 shares outstanding
                                                5,575,000                                            
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,572,647 shares outstanding
                                                1,573,000                                            
        class a, par value 1 per share, 5,662,214 shares outstanding
                                                 5,662,000                                           
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,573,292 shares outstanding
                                                 1,573,000                                           
        accumulated other comprehensive income
                                                 -20,189,000    -12,259,000    -65,100,000                                   
        coal supply agreements and other intangibles
                                                  57,017,000 57,929,000 58,920,000 59,685,000 60,617,000 61,693,000  63,400,000           64,400,000 65,200,000 65,900,000 66,700,000 68,500,000 69,400,000 70,300,000 71,000,000 71,700,000 72,600,000 73,400,000 74,200,000 73,700,000 74,500,000 75,100,000 75,900,000 76,900,000 77,700,000 78,500,000 78,400,000 79,000,000 79,900,000 80,800,000 81,600,000 
        long-term deferred income taxes
                                                  23,304,000 23,026,000 22,918,000 24,786,000 23,074,000 22,961,000 24,632,000 27,300,000  4,000,000 3,700,000 3,500,000 2,300,000 3,700,000 5,000,000 12,600,000 13,300,000 11,800,000 21,400,000 16,500,000 22,800,000 21,300,000 10,200,000 18,300,000 17,500,000 17,600,000                 
        class a, par value 1 per share, 5,821,078 shares outstanding
                                                  5,821,000                                          
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,573,804 shares outstanding
                                                  1,574,000                                          
        class a, par value 1 per share, 6,046,238 shares outstanding
                                                   6,046,000                                         
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,580,590 shares outstanding
                                                   1,581,000                                         
        class a, par value 1 per share, 6,218,289 shares outstanding
                                                    6,218,000                                        
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,580,870 shares outstanding
                                                    1,581,000                                        
        class a, par value 1 per share, 6,290,414 shares outstanding
                                                     6,290,000                                       
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,581,106 shares outstanding
                                                     1,581,000                                       
        class a, par value 1 per share, 6,356,996 shares outstanding
                                                      6,357,000                                      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,581,406 shares outstanding
                                                      1,581,000                                      
        class a, par value 1 per share, 6,454,764 shares outstanding
                                                       6,455,000                                     
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,581,835 shares outstanding
                                                       1,582,000                                     
        noncontrolling interest
                                                           800,000 800,000 800,000 700,000 700,000 800,000 500,000 400,000 500,000 300,000 400,000 200,000                      
        total equity
                                                       268,026,000  281,400,000 291,100,000 616,700,000 610,700,000 577,000,000 547,800,000 541,200,000 516,700,000 387,300,000 388,500,000 397,100,000 369,400,000 372,200,000 340,900,000                      
        coal supply agreement and other intangibles
                                                        62,312,000  71,900,000       61,400,000 62,800,000 63,500,000                         
        class a, par value 1 per share, 6,756,482 shares outstanding
                                                        6,756,000                                    
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,582,155 shares outstanding
                                                        1,582,000                                    
        class a, par value 1 per share, 6,770,689 shares outstanding
                                                         6,800,000                                   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,582,310 shares outstanding
                                                         1,600,000                                   
        class a, par value 1 per share, 6,803,999 shares outstanding
                                                          6,800,000                                  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,590,311 shares outstanding
                                                          1,600,000                                  
        coal supply agreement
                                                           56,800,000 57,300,000 57,900,000 58,500,000 59,100,000 59,600,000                            
        revolving credit agreements - not guaranteed by the parent company
                                                           62,700,000 45,000,000  23,500,000 23,500,000 21,000,000        70,800,000              23,600,000 27,100,000 55,200,000  33,200,000 33,300,000 
        current maturities of long-term debt - not guaranteed by the parent company
                                                           37,000,000 229,900,000  124,900,000 73,800,000 20,000,000        35,700,000              26,800,000 15,200,000 30,500,000  27,600,000 38,700,000 
        long-term debt - not guaranteed by the parent company
                                                           207,800,000 63,500,000  188,400,000 300,800,000 354,000,000        409,800,000      370,400,000  373,000,000    405,400,000  413,300,000 407,400,000 383,400,000 390,400,000 355,600,000 363,200,000 
        class a, par value 1 per share, 6,799,142 shares outstanding
                                                           6,800,000                                 
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,590,421 shares outstanding
                                                           1,600,000                                 
        class a, par value 1 per share, 6,795,404 shares outstanding
                                                            6,800,000                                
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,592,571 shares outstanding
                                                            1,600,000                                
        revolving credit agreements — not guaranteed by the parent company
                                                             67,000,000    24,500,000 19,400,000 9,500,000 26,400,000 36,100,000 66,000,000 6,400,000  61,800,000 96,800,000 31,900,000 70,600,000 59,600,000 35,200,000 28,300,000 55,500,000 45,900,000 39,200,000 35,900,000 57,900,000 25,300,000    22,600,000   
        current maturities of long-term debt — not guaranteed by the parent company
                                                             178,100,000    22,700,000 24,500,000 22,400,000 44,500,000 45,600,000 48,700,000 42,600,000  39,800,000 39,400,000 35,200,000 30,400,000 30,900,000 26,300,000 28,300,000 30,100,000 29,100,000 49,500,000 25,100,000 23,900,000 23,100,000    27,900,000   
        long-term debt — not guaranteed by the parent company
                                                             129,100,000    367,700,000 372,400,000 377,600,000 380,700,000 381,600,000 380,600,000 400,500,000  415,700,000 419,100,000 439,500,000 449,800,000 456,800,000  359,900,000  373,100,000 379,900,000 406,200,000         
        class a, par value 1 per share, 6,778,346 shares outstanding
                                                             6,800,000                               
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,595,581 shares outstanding
                                                             1,600,000                               
        accumulated other comprehensive income:
                                                                                            
        foreign currency translation adjustment
                                                             13,200,000 20,400,000 44,700,000 38,300,000 8,800,000 21,600,000 34,800,000 36,500,000 27,800,000 7,100,000 17,400,000 47,600,000 85,000,000 78,100,000 66,800,000 59,400,000 49,800,000 42,600,000 38,400,000 30,000,000 26,700,000 19,900,000 18,000,000 25,900,000 26,900,000 38,300,000 46,400,000 24,900,000 20,600,000 25,800,000  
        deferred gain on cash flow hedging
                                                             2,600,000    -3,400,000 -1,200,000 3,500,000 4,900,000 9,500,000   3,300,000     700,000   2,300,000 7,000,000 2,600,000          
        pension and postretirement plan adjustment
                                                             -90,400,000 -72,800,000 -74,400,000 -76,200,000 -76,600,000 -78,000,000 -79,400,000                         
        class a, par value 1 per share, 6,800,615 shares outstanding
                                                              6,800,000                              
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,595,781 shares outstanding
                                                              1,600,000 1,600,000                             
        deferred loss on cash flow hedging
                                                              -3,500,000 -10,800,000 -11,800,000      -2,700,000 -9,100,000  -5,000,000 -11,500,000 -5,700,000 -2,200,000  -1,000,000 -400,000    -2,700,000 -2,800,000 -3,700,000 -2,900,000 -2,800,000 -5,900,000 -6,000,000 -8,100,000  
        class a, par value 1 per share, 6,798,464 shares outstanding
                                                               6,800,000                             
        class a, par value 1 per share, 6,797,071 shares outstanding
                                                                6,800,000                            
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,596,011 shares outstanding
                                                                1,600,000                            
        accrued warranty
                                                                 24,700,000 25,400,000 27,900,000 31,700,000 36,500,000 38,900,000 46,300,000 46,500,000 45,900,000                   
        class a, par value 1 per share, 6,735,232 shares outstanding
                                                                 6,700,000                           
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,596,396 shares outstanding
                                                                 1,600,000                           
        class a, par value 1 per share, 6,732,082 shares outstanding
                                                                  6,700,000                          
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,598,603 shares outstanding
                                                                  1,600,000                          
        class a, par value 1 per share, 6,694,380 shares outstanding
                                                                   6,700,000                         
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,599,356 shares outstanding
                                                                   1,600,000                         
        pension and other post-retirement obligations
                                                                    83,000,000 89,800,000 98,200,000 100,900,000 63,800,000 69,400,000 72,000,000 74,200,000                 
        class a, par value 1 per share, 6,692,977 shares outstanding
                                                                    6,700,000                        
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,599,396 shares outstanding
                                                                    1,600,000                        
        pension and post-retirement plan adjustment
                                                                    -70,200,000 -71,400,000 -72,500,000 -73,600,000 -42,900,000 -43,900,000 -45,000,000 -47,000,000 -54,400,000 -55,500,000 -56,800,000 -58,200,000             
        class a, par value 1 per share, 6,686,451 shares outstanding
                                                                     6,700,000                       
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,604,336 shares outstanding
                                                                     1,600,000                       
        class a, par value 1 per share, 6,684,175 shares outstanding
                                                                      6,700,000                      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,604,397 shares outstanding
                                                                      1,600,000                      
        liabilities and stockholders’ equity
                                                                                            
        minority interest
                                                                       200,000 300,000 100,000       100,000 200,000 200,000     100,000  100,000 200,000 500,000 
        class a, par value 1 per share, 6,680,652 shares outstanding
                                                                       6,700,000                     
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,605,226 shares outstanding
                                                                       1,600,000                     
        total liabilities and stockholders’ equity
                                                                       1,687,900,000 2,337,000,000 2,367,800,000 2,427,500,000 2,428,200,000 2,351,500,000 2,232,100,000 2,088,000,000 2,156,300,000 2,116,500,000 2,020,200,000 2,036,100,000 2,094,000,000 2,066,100,000 2,002,800,000 2,043,500,000 2,038,600,000 1,909,600,000 1,857,100,000 1,833,300,000  
        class a, par value 1 per share, 6,677,651 shares outstanding
                                                                        6,700,000                    
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,605,865 shares outstanding
                                                                        1,600,000                    
        class a, par value 1 per share, 6,675,721 shares outstanding
                                                                         6,700,000                   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,606,922 shares outstanding
                                                                         1,600,000                   
        class a, par value 1 per share, 6,674,275 shares outstanding
                                                                          6,700,000                  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,607,342 shares outstanding
                                                                          1,600,000                  
        class a, par value 1 per share, 6,661,102 shares outstanding
                                                                           6,700,000                 
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,607,442 shares outstanding
                                                                           1,600,000                 
        self-insurance and other liabilities
                                                                            269,100,000 272,000,000 272,500,000 252,300,000 276,800,000 275,900,000 279,800,000 279,800,000 274,400,000  269,600,000 271,100,000 253,900,000 249,700,000 253,500,000 249,300,000 
        class a, par value 1 per share, 6,660,185 shares outstanding
                                                                            6,700,000                
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,607,486 shares outstanding
                                                                            1,600,000                
        class a, par value 1 per share, 6,658,150 shares outstanding
                                                                             6,700,000               
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,608,821 shares outstanding
                                                                             1,600,000               
        class a, par value 1 per share, 6,657,095 shares outstanding
                                                                              6,700,000              
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,609,341 shares outstanding
                                                                              1,600,000              
        class a, par value 1 per share, 6,628,483 shares outstanding
                                                                               6,700,000             
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,609,513 shares outstanding
                                                                               1,600,000             
        accrued warranty obligations
                                                                                29,200,000 28,300,000 28,400,000 27,800,000 28,700,000 28,800,000 28,400,000 28,400,000    25,900,000 
        class a, par value 1 per share, 6,627,528 shares outstanding
                                                                                6,600,000            
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,609,841 shares outstanding
                                                                                1,600,000            
        minimum pension liability adjustment
                                                                                -57,600,000 -57,600,000 -57,500,000 -57,000,000 -52,100,000 -52,100,000 -52,100,000 -52,100,000 -42,300,000 -42,300,000 -42,300,000  
        class a, par value 1 per share, 6,626,585 shares outstanding
                                                                                 6,600,000           
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,610,078 shares outstanding
                                                                                 1,600,000           
        class a, par value 1 per share, 6,625,130 shares outstanding
                                                                                  6,600,000          
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,610,798 shares outstanding
                                                                                  1,600,000          
        class a, par value 1 per share, 6,615,059 shares outstanding
                                                                                   6,600,000         
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,611,378 shares outstanding
                                                                                   1,600,000         
        class a, par value 1 per share, 6,612,720 shares outstanding
                                                                                    6,600,000        
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,612,854 shares outstanding
                                                                                    1,600,000        
        long—term debt — not guaranteed by the parent company
                                                                                     412,100,000       
        self—insurance and other liabilities
                                                                                     265,500,000       
        class a, par value 1 per share, 6,610,865 shares outstanding
                                                                                     6,600,000       
        class b, par value 1 per share, convertible into class a on a one—for—one basis, 1,613,839 shares outstanding
                                                                                     1,600,000       
        class a, par value 1 per share, 6,608,964 shares outstanding
                                                                                      6,600,000      
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,615,065 shares outstanding
                                                                                      1,600,000      
        class a, par value 1 per share, 6,597,161 shares outstanding
                                                                                       6,600,000     
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,617,221 shares outstanding
                                                                                       1,600,000     
        class a, par value 1 per share, 6,596,336 shares outstanding
                                                                                        6,600,000    
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,617,391 shares outstanding
                                                                                        1,600,000    
        class a, par value 1 per share, 6,593,593 shares outstanding
                                                                                         6,600,000   
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,619,301 shares outstanding
                                                                                         1,600,000   
        class a, par value 1 per share, 6,592,018 shares outstanding
                                                                                          6,600,000  
        class b, par value 1 per share, convertible into class a on a one-for-one basis, 1,620,091 shares outstanding
                                                                                          1,600,000  
      Cashflow Statements:
      Quarterly
      Annual
        Unit: USD2026-03-31 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 2021-09-30 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 2010-06-30 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 2004-09-30 2004-06-30 2004-03-31 
                                                                                             
          operating activities
                                                                                             
          net cash from operating activities
        12,374,000 42,255,000 -7,776,000 5,023,000 25,168,000 2,819,000 4,060,000 -9,758,000 -8,530,000 39,733,000 17,033,000 6,254,000 12,806,000 14,448,000 41,551,000 -1,070,000 38,476,000 30,228,000 -910,000 -5,246,000 15,249,000 18,633,000 -31,122,000 5,520,000 25,176,000 22,632,000 -544,000 15,771,000 20,155,000 26,725,000 -8,029,000 14,187,000 28,865,000 40,457,000 -42,204,000 47,777,000 29,189,000 20,788,000 -3,819,000 48,188,000      4,604,000 -26,016,000       49,200,000 2,500,000 103,900,000 -4,600,000 64,700,000 -8,800,000 54,900,000 -15,500,000 80,600,000 34,500,000 62,900,000 -21,000,000 49,900,000 6,400,000 33,800,000 -85,200,000 117,500,000 -8,900,000 41,900,000 -68,900,000 144,200,000 12,000,000 30,300,000 -13,000,000 124,500,000 -3,200,000 -12,400,000 -33,700,000 154,100,000 -29,200,000 -11,800,000 13,100,000 
          capital expenditures
        -33,430,000 -22,392,000 -3,142,000 -8,808,000 -8,296,000 -7,918,000 -14,483,000 -23,759,000 -6,256,000 -7,879,000 -17,086,000 -20,269,000 -4,649,000 -19,407,000 -11,251,000 -4,876,000 -10,385,000 -7,003,000 -7,441,000 -5,358,000 -11,400,000 -7,297,000 -1,715,000 -4,252,000 -6,298,000 -5,450,000 -6,730,000 -2,452,000 -6,493,000 -1,112,000 -3,449,000 -4,650,000 -4,478,000 -2,995,000 -4,335,000 -4,359,000 -3,131,000      -9,335,000 -31,845,000       -34,800,000 -5,500,000 -10,400,000 -9,800,000 -10,300,000 -6,200,000 -5,700,000 -4,700,000 -9,700,000 -7,700,000 -7,100,000 -9,000,000 -14,400,000 -18,000,000 -21,500,000 -18,000,000 -27,100,000 -10,700,000 -12,800,000 -18,200,000 -29,900,000 -12,800,000 -13,300,000 -18,600,000 -19,100,000 -20,000,000 -16,500,000 -15,100,000 -16,100,000 -14,600,000 -15,700,000 -10,800,000 
          free cash flows
        -21,056,000 19,863,000 -10,918,000 -3,785,000 25,168,000 -5,477,000 -3,858,000 -24,241,000 -8,530,000 15,974,000 10,777,000 -1,625,000 12,806,000 -2,638,000 21,282,000 -5,719,000 19,069,000 18,977,000 -5,786,000 -15,631,000 8,246,000 11,192,000 -36,480,000 -5,880,000 17,879,000 20,917,000 -4,796,000 9,473,000 14,705,000 19,995,000 -10,481,000 7,694,000 27,753,000 37,008,000 -46,854,000 43,299,000 26,194,000 16,453,000 -8,178,000 45,057,000      -4,731,000 -57,861,000       14,400,000 -3,000,000 93,500,000 -14,400,000 54,400,000 -15,000,000 49,200,000 -20,200,000 70,900,000 26,800,000 55,800,000 -30,000,000 35,500,000 -11,600,000 12,300,000 -103,200,000 90,400,000 -19,600,000 29,100,000 -87,100,000 114,300,000 -800,000 17,000,000 -31,600,000 105,400,000 -23,200,000 -28,900,000 -48,800,000 138,000,000 -43,800,000 -27,500,000 2,300,000 
          investing activities
                                                                                             
          expenditures for property, plant and equipment and acquisition of mineral interests
        -33,430,000 -22,392,000 -3,142,000 -8,808,000  -8,296,000 -7,918,000 -14,483,000  -23,759,000 -6,256,000 -7,879,000  -17,086,000 -20,269,000 -4,649,000 -19,407,000 -11,251,000 -4,876,000                                                                   
          proceeds from the sale of assets
        6,000                                               1,188,000 42,000 320,000 954,000 1,400,000 10,800,000 3,100,000 20,600,000 2,900,000 300,000   3,700,000 500,000 7,400,000 700,000 7,700,000 4,900,000 2,200,000 700,000 600,000 1,800,000 500,000 500,000 700,000 1,000,000 31,300,000 2,200,000 12,200,000 2,100,000 2,600,000 3,400,000 2,100,000 2,500,000  2,400,000 1,400,000 3,900,000 
          return of equity method investment
        999,000                                                                                     
          other
        -100,000 345,000 588,000 207,000 -3,197,000 191,000 -802,000 -163,000 2,105,000 -1,122,000 -5,000 -10,000 -733,000 -36,000 -7,000 -15,000 -31,000 -6,000 -15,000 -3,858,000 467,000 -411,000 16,000 -7,385,000 2,000 -9,000 -13,000 -5,225,000 417,000 288,000 -3,426,000 15,213,000 -40,000 8,242,000 -7,592,000 3,300,000 220,000 102,000 -1,973,000 2,287,000 6,389,000 1,294,000 -8,216,000 4,581,000 2,517,000 11,128,000 -3,559,000 1,896,000 -2,213,000 3,928,000 -18,183,000 12,000,000 -13,500,000 7,900,000 5,400,000 -3,800,000 4,700,000 6,200,000 3,200,000 -1,300,000 -1,900,000 33,600,000 -6,600,000 -17,600,000 -8,800,000 16,500,000 -200,000 -7,100,000 1,700,000 -10,500,000 -5,100,000 5,800,000 3,400,000 -2,200,000 -5,900,000 -2,900,000 3,000,000 6,100,000 100,000 -4,300,000 -400,000 -1,400,000 700,000   
          net cash from investing activities
        -32,525,000 -21,775,000 -2,506,000 -8,529,000 -40,237,000 -7,780,000 -8,640,000 -14,635,000 -44,042,000 -24,856,000 -6,235,000 -6,464,000 6,086,000 -17,122,000 -17,587,000 -4,529,000 -18,950,000 -11,242,000 -4,847,000 -24,804,000 -6,536,000 -9,302,000 -5,342,000 -11,453,000 -2,857,000 -1,705,000 -4,247,000 -4,965,000 -5,142,000 -6,192,000 -2,088,000 -4,356,000 -4,641,000 -2,172,000 -3,836,000 112,000 -1,323,000 -5,283,000 -3,323,000 -1,967,000 -3,260,000 -1,542,000 -1,522,000  -6,497,000 -8,898,000 -31,902,000       -17,300,000 15,100,000 -7,400,000 -9,500,000 -10,000,000 -5,800,000 -2,200,000 -5,100,000 37,200,000 -9,100,000 -100,000 -4,900,000 -14,800,000 -18,400,000 -22,000,000 -16,200,000 -25,000,000 -5,900,000 -11,800,000 -17,200,000 1,400,000 -23,800,000 300,000 -13,200,000 -15,600,000 -17,600,000 -10,500,000 -12,600,000 -8,800,000 -10,300,000 -14,300,000 -6,900,000 
          financing activities
                                                                                             
          net additions (reductions) to revolving credit agreement
        25,000,000                                                                                     
          reductions to long-term debt
        -1,169,000                                                                                     
          additions to note payable to affiliate
        1,676,000                                                                                     
          cash dividends paid
        -1,903,000 -1,882,000 -1,879,000 -1,691,000 -1,660,000 -1,658,000 -1,676,000 -1,630,000 -1,626,000 -1,636,000 -1,633,000 -1,557,000 -1,524,000 -1,522,000 -1,521,000 -1,445,000 -1,414,000 -1,412,000 -1,374,000 -1,330,000 -1,355,000 -1,351,000 -1,339,000 -1,324,000 -1,328,000 -1,327,000 -1,153,000 -1,145,000 -1,144,000 -1,145,000 -1,144,000 -1,130,000 -1,862,000 -1,863,000 -1,827,000 -1,812,000 -1,812,000 -1,834,000 -1,804,000 -1,794,000 -1,814,000 -1,838,000 -1,850,000 -1,871,000 -1,927,000 -1,993,000 -1,964,000 -1,971,000 -1,999,000 -2,032,000 -2,102,000 -31,400,000 -4,600,000 -4,600,000 -4,500,000 -4,500,000 -4,400,000 -4,500,000 -4,400,000 -4,400,000 -4,300,000 -4,200,000 -4,300,000 -4,300,000 -4,300,000 -4,300,000 -4,200,000 -4,300,000 -4,100,000 -4,200,000 -4,100,000 -4,100,000 -4,000,000 -4,000,000 -3,900,000 -4,000,000 -3,800,000 -3,900,000 -3,800,000 -3,800,000 -3,700,000 -3,800,000 -3,700,000 -3,200,000 -3,100,000 
          purchase of treasury shares
         -695,000 -368,000 -2,017,000 -3,285,000 -4,274,000 -2,279,000           -1,002,000 -1,600,000 -25,000 -85,000 -1,300,000 -955,000 -284,000       -2,218,000   -762,000 -7,239,000 -9,098,000 -6,911,000 -8,628,000 -12,200,000 -9,261,000 -4,986,000 -3,951,000 -5,747,000 -16,508,000 -5,100,000 -2,600,000 -600,000                               
          net cash from financing activities
        23,604,000 -17,225,000 -2,200,000 -7,443,000 24,850,000 5,652,000 5,097,000 1,128,000 9,514,000 -3,726,000 -3,419,000 -901,000 -898,000 -1,685,000 -8,471,000 1,214,000 -17,031,000 -13,106,000 -3,561,000 20,933,000 -6,692,000 -7,511,000 7,298,000 13,764,000 -5,681,000 -1,562,000 -1,408,000 -8,599,000 -11,915,000 -23,984,000 -8,080,000 -2,169,000 12,612,000 -34,214,000 21,465,000 -11,352,000 -17,862,000 -16,844,000 -9,652,000 -5,577,000 -14,151,000 -20,816,000 -67,757,000  -27,392,000 -4,897,000 32,601,000       -40,500,000 -44,300,000 28,700,000 -65,900,000 -3,800,000 -1,000,000 -9,900,000 2,200,000 -45,800,000 -18,000,000 -43,500,000 43,200,000 -73,000,000 -3,900,000 -46,800,000 40,600,000 -50,200,000 1,400,000 106,100,000 7,100,000 -54,500,000 4,600,000 -44,400,000 -11,500,000 -28,200,000 21,900,000 -6,200,000 10,700,000 -29,000,000 25,500,000 21,600,000 -22,200,000 
          cash and cash equivalents
                                                                                             
          total increase for the period
        3,453,000     691,000    11,151,000    -4,359,000       2,021,000    16,638,000                                                             
          balance at the beginning of the period
        49,708,000 72,833,000  85,109,000  110,748,000  86,005,000 88,450,000  122,892,000  85,257,000  101,600,000  -11,340,000 80,648,000  52,499,000  61,135,000  95,390,000  139,855,000  -184,900,000 338,600,000  261,900,000 256,200,000  138,300,000  281,400,000  196,700,000  166,500,000  150,400,000  68,900,000 
          balance at the end of the period
        53,161,000 3,255,000 -12,482,000 61,884,000  691,000 517,000 61,844,000  11,151,000 7,379,000 109,637,000  -4,359,000 15,493,000 81,620,000 2,495,000 5,880,000 79,132,000  2,021,000 1,820,000 93,726,000  16,638,000 19,365,000 79,058,000  3,098,000 -3,451,000 83,403,000  33,729,000 3,783,000 56,426,000  10,009,000 -1,461,000 35,718,000  -7,476,000 -9,989,000 29,312,000  -10,309,000 -9,163,000 70,070,000  -5,705,000 -11,812,000 96,870,000  -147,500,000 -11,700,000 314,900,000  -83,900,000 51,700,000 249,800,000 36,700,000 233,300,000  8,800,000 23,000,000 155,800,000  -16,000,000 -34,800,000 222,300,000  -13,700,000 136,600,000 117,200,000  -6,400,000 -16,800,000 128,800,000  1,600,000 -29,400,000 112,800,000  -12,600,000 -5,100,000 49,900,000 
          balance, january 1, 2025
        5,730,000 5,730,000                                                                                  
          stock-based compensation
        169,000 130,000 5,671,000 161,000 5,012,000 145,000 7,449,000 92,000 88,000 2,976,000 102,000 4,837,000 87,000                                                           
          net income
                                   11,016,000 9,200,000 6,393,000 8,176,000 10,173,000 8,398,000 6,788,000 4,978,000 24,131,000 -442,000 3,116,000 2,802,000 18,091,000 3,141,000 -275,000 1,027,000 -40,669,000 7,699,000 -3,624,000 -1,524,000 22,556,000 12,325,000 5,147,000 4,422,000 23,700,000 38,000,000 21,800,000 25,200,000 54,500,000 25,700,000 19,100,000 62,800,000 16,000,000 11,600,000   1,400,000 -9,100,000 -425,300,000 -17,400,000 2,400,000 2,700,000 51,700,000 21,100,000 9,900,000 6,600,000 70,000,000 18,800,000 4,700,000 12,700,000 32,400,000 13,600,000 11,300,000 5,200,000 32,600,000 13,400,000 6,400,000 -4,500,000 
          cash dividends on class a and class b common stock: 0.2275 per share
                                                                                             
          reclassification adjustment to net income, net of tax
                                                                                             
          balance, march 31, 2025
        5,877,000 5,877,000                                                                                  
          balance, january 1, 2026
        5,864,000                                                                                     
          cash dividends on class a and class b common stock: 0.2525 per share
                                                                                             
          balance, march 31, 2026
        5,978,000                                                                                     
          proceeds from the sale of property, plant and equipment
         272,000 48,000 72,000  325,000 80,000 11,000  25,000 26,000 272,000  2,689,000 135,000 488,000 15,000 44,000     4,438,000 19,000 18,000  66,000 219,000 55,000  532,000                                                     
          additions to long-term debt
         825,000 847,000 1,096,000 -2,466,000 853,000 910,000 1,327,000 4,442,000 -331,000 -991,000 2,112,000 1,427,000 555,000 -2,239,000 3,348,000   170,000 1,228,000 -103,000 70,000 6,232,000 935,000 -153,000 12,000 1,206,000  68,000 -578,000 1,269,000   732,000 5,461,000    137,000  500,000 -829,000 2,876,000  1,553,000  -257,000 -1,025,000 2,793,000  -138,900,000 159,200,000 4,700,000 4,500,000 3,800,000 5,000,000 3,300,000 1,900,000 2,700,000 4,500,000 2,700,000 200,000 5,600,000 7,600,000 6,400,000 9,400,000 8,300,000 3,300,000 24,100,000 112,700,000 7,300,000 -400,000 4,600,000 231,300,000 12,300,000         
          reductions of long-term debt
         -1,168,000 -1,168,000 -1,153,000  -1,247,000 -1,352,000 -1,295,000  -935,000 -795,000 -1,456,000  -718,000 1,289,000 -2,689,000 -250,000 -2,524,000 -357,000  -234,000 -230,000 -593,000  -175,000 -162,000 -161,000  -10,555,000 -22,206,000 -8,205,000 28,961,000 -10,194,000 -24,382,000 -432,000 -17,004,000 -12,937,000 -13,851,000 -2,772,000 -3,982,000 -1,572,000 -365,000 -363,000 -7,399,000 -290,000 -1,356,000 -354,000 -4,041,000 3,502,000 -5,132,000 -10,132,000 -7,900,000 223,100,000 -257,400,000 -20,300,000 -11,900,000 -64,900,000 -6,800,000 -7,200,000 -9,900,000 -6,200,000 -27,600,000 -8,500,000 -7,200,000 -18,200,000 -13,200,000 -16,500,000 -16,400,000 -25,800,000 -12,400,000 -25,000,000 -10,400,000 -19,000,000 -24,200,000 -8,100,000 -264,200,000 -20,400,000         
          net (reductions) additions to revolving credit agreements
         -15,000,000 -5,000,000               -2,000,000                                                                   
          total decrease for the period
         3,255,000 -12,482,000 -10,949,000    -23,265,000    -1,111,000    -4,385,000 2,495,000 5,880,000 -9,318,000    -29,166,000    -6,199,000   -3,451,000 -18,197,000                                                       
          balance, january 1, 2024
         5,883,000  5,883,000                                                                              
          cash dividends on class a and class b common stock: 0.2175 per share
                                                                                             
          balance, march 31, 2024
         5,885,000  5,885,000                                                                              
          balance, june 30, 2024
                                                                                           
          balance, september 30, 2024
                                                                                             
          conversion of class b to class a shares
                1,000  1,000 1,000                                                                  
          balance, june 30, 2025
                                                                                            
          balance, september 30, 2025
                                                                                             
          adjustments to reconcile net income to net cash from operating activities:
                                                                                             
          depreciation, depletion and amortization
                                   3,748,000 3,815,000 3,723,000 3,397,000 3,187,000 675,000 4,417,000 4,488,000 5,353,000 5,215,000 4,516,000 4,192,000 6,343,000 5,778,000 5,801,000 5,758,000 8,625,000 6,848,000 6,618,000 5,979,000 8,195,000 6,168,000 4,837,000 5,372,000 6,600,000 -9,200,000 10,300,000 10,300,000 12,200,000 12,600,000 11,400,000 11,500,000 13,300,000 12,900,000 12,900,000 13,900,000 13,200,000 13,600,000 14,600,000 15,400,000 15,100,000 15,400,000 15,100,000 15,900,000 14,800,000 15,000,000 16,800,000 16,000,000 15,100,000 14,800,000 16,800,000 15,500,000 15,200,000 16,100,000 15,500,000 15,600,000 15,700,000 16,100,000 
          amortization of deferred financing fees
                                   83,000 84,000 83,000 84,000 84,000 91,000 148,000 148,000 148,000 134,000 157,000 157,000 143,000 156,000 159,000 631,000 -118,000 77,000 86,000 184,000 172,000 147,000 146,000 149,000 100,000 -600,000 1,000,000 600,000 700,000 600,000 700,000 700,000 600,000 500,000 700,000 500,000 500,000 500,000 500,000 500,000 500,000 500,000 600,000 500,000 400,000 500,000 400,000 500,000 600,000 700,000 600,000 800,000 900,000 1,100,000 900,000 1,000,000   
          deferred income taxes
                                   3,867,000 2,115,000 1,802,000 1,497,000 358,000 -810,000 2,494,000 2,047,000 -5,504,000 6,185,000 3,591,000 8,425,000 -2,306,000 -7,528,000 -2,258,000 5,150,000 -42,341,000 1,242,000 -2,044,000 1,796,000 -245,000 -4,068,000 -5,143,000 1,810,000 10,300,000 9,300,000 -8,400,000 3,400,000 8,600,000 -5,500,000 -900,000 12,200,000 900,000 2,800,000 15,200,000 -1,900,000 7,400,000 4,000,000 4,200,000 10,300,000 -8,400,000 14,200,000 -1,800,000 -1,200,000 3,600,000 3,500,000 -4,700,000 4,800,000 3,900,000 4,700,000 -9,000,000 -800,000 2,900,000 -700,000 -2,400,000 800,000 -4,100,000 3,800,000 
          (gain) loss on sale of assets
                                                                                             
          inventory impairment charges
                                                                                             
          long-lived asset impairment charge
                                                                                             
          working capital changes:
                                                                                             
          accounts receivable
                                   -7,075,000 5,417,000 -1,029,000 -321,000 -6,519,000 -29,659,000 -3,107,000 29,974,000 -19,577,000 -23,399,000 -2,536,000 35,095,000 6,729,000 -29,649,000 5,690,000 83,716,000 -33,017,000 -20,955,000 -14,841,000 46,307,000 -14,978,000 -28,135,000 7,750,000 32,584,000 -11,800,000 -50,100,000 14,900,000 27,900,000 12,100,000 -68,400,000 32,800,000 -25,600,000 -7,900,000 -6,400,000 -10,700,000 -17,200,000 33,900,000 120,800,000 -3,700,000 -19,500,000 2,700,000 35,600,000 -54,200,000 -78,600,000 9,100,000 11,400,000 14,100,000 -45,300,000 -9,800,000 23,900,000 -22,000,000 -9,600,000 -15,600,000 13,700,000 -9,300,000 -37,900,000 -2,100,000 22,900,000 
          inventories
                                   1,973,000 -4,023,000 957,000 -100,000 564,000 4,756,000 -4,798,000 -1,651,000 43,967,000 -36,297,000 -3,400,000 632,000 67,981,000 -31,047,000 -16,071,000 3,286,000 35,304,000 -32,460,000 5,746,000 -9,469,000 22,905,000 -39,846,000 -5,614,000 7,684,000 41,400,000 -33,200,000 -9,000,000 -2,000,000 66,700,000 -68,200,000 -1,500,000 -30,400,000 -14,500,000 1,600,000 55,200,000 -11,100,000 96,700,000 22,200,000 85,500,000 -48,600,000 49,800,000 -50,200,000 32,400,000 -64,300,000 -4,200,000 -5,800,000 44,200,000 -49,100,000 8,400,000 -9,800,000 70,300,000 -47,600,000 -600,000 -63,500,000 29,400,000 -34,600,000 -39,400,000 -32,900,000 
          other current assets
                                   -1,152,000 2,706,000 57,000 -2,119,000 -882,000 3,132,000 -510,000 -2,722,000 -3,562,000 815,000 2,322,000 -2,207,000 2,474,000 3,916,000 6,781,000 -8,641,000 8,122,000 1,242,000 -1,214,000 -7,949,000 1,746,000 1,583,000 3,604,000 -7,735,000 3,600,000 2,800,000 5,900,000 -13,300,000 2,700,000 2,800,000 3,600,000 -11,800,000 -2,600,000 -7,500,000 11,700,000 5,700,000 11,700,000 -16,000,000 9,100,000 10,300,000 3,300,000 -27,100,000 3,000,000 4,900,000 -2,000,000 -10,400,000 9,800,000 2,400,000 -2,200,000 -7,900,000 8,100,000 1,100,000 3,200,000 -13,400,000 23,400,000 7,000,000 -1,700,000 -22,100,000 
          accounts payable
                                   -432,000 -3,682,000 5,309,000 -1,135,000 -1,240,000 24,674,000 19,069,000 -41,454,000 -28,089,000 56,414,000 11,353,000 -12,580,000 -57,923,000 45,521,000 8,335,000 -24,800,000 -19,847,000 50,579,000 -6,796,000 -26,899,000 -8,992,000 51,581,000 124,000 -37,862,000 -11,500,000 47,500,000 -6,900,000 -5,200,000 -58,600,000 76,100,000 -11,800,000 -1,400,000 46,100,000 3,700,000 -6,600,000 60,800,000 -56,600,000 -107,200,000 -109,600,000 56,500,000 -40,500,000 -15,200,000 44,000,000 75,000,000 -6,500,000 -42,100,000 1,600,000 54,900,000 -9,100,000 -14,600,000         
          income taxes receivable/payable
                                   -306,000 -691,000 -357,000 -1,124,000 -4,531,000 5,781,000    -10,939,000 -3,910,000 -6,062,000  -1,834,000                                             
          other current liabilities
                                   6,146,000 4,508,000 2,983,000 -12,862,000 2,418,000 20,435,000 7,901,000 -30,420,000 6,553,000 13,840,000 5,477,000 -32,300,000 -2,326,000 15,090,000 9,625,000 -20,439,000 -839,000 6,841,000 9,545,000 -30,882,000 10,113,000 13,139,000 7,513,000 -14,902,000 -8,200,000 34,300,000 11,900,000 -46,800,000 11,600,000 16,800,000 4,400,000 -25,500,000                           
          expenditures for property, plant and equipment
                           -10,385,000 -7,003,000 -7,441,000 -5,358,000 -11,400,000 -7,297,000 -1,715,000 -4,252,000 -6,298,000 -5,450,000 -6,730,000 -2,452,000 -6,493,000 -1,112,000 -3,449,000 -4,650,000 -4,478,000 -2,995,000 -4,335,000 -4,359,000 -3,131,000 -3,332,000 -1,766,000 -2,386,000 -9,837,000 -6,483,000 -9,335,000 -31,845,000 -32,544,000 -11,089,000 -6,351,000 -7,465,000 -5,000,000 600,000 -34,800,000 -5,500,000 -10,400,000 -9,800,000 -10,300,000 -6,200,000 -5,700,000 -4,700,000 -9,700,000 -7,700,000 -7,100,000 -9,000,000 -14,400,000 -18,000,000 -21,500,000 -18,000,000 -27,100,000 -10,700,000 -12,800,000 -18,200,000 -29,900,000 -12,800,000 -13,300,000 -18,600,000 -19,100,000 -20,000,000 -16,500,000 -15,100,000 -16,100,000 -14,600,000 -15,700,000 -10,800,000 
          acquisition of mineral interests
                                                                                             
          equity method investment
                                                                                             
          proceeds from the sale of private company equity units
                2,421,000 1,153,000                                                                          
          net additions to revolving credit agreement
                                                                                             
          debt issuance costs
                                                                                             
          total decrease for the year
                                                                                             
          balance at the beginning of the year
                                                                                             
          balance at the end of the year
                                                                                             
          net additions to revolving credit agreements
             9,721,000 10,500,000 7,000,000               4,000,000                         14,518,000    -4,200,000 41,500,000   43,500,000 2,400,000 7,400,000 5,300,000 10,000,000  -8,100,000 -32,200,000 60,300,000  10,500,000 -35,500,000 62,200,000  6,200,000 10,500,000 22,800,000  12,100,000 5,400,000 4,100,000         
          balance, january 1, 2023
             5,783,000  5,783,000                                                                          
          cash dividends on class a and class b common stock: 0.2075 per share
                                                                                             
          balance, march 31, 2023
             5,944,000  5,944,000                                                                          
          balance, june 30, 2023
                                                                                           
          net loss
                                                                                             
          balance, september 30, 2023
                                                                                             
          loss on sale of assets
                                                        -48,000 5,000 346,000                    -200,000 -400,000 100,000 -21,500,000 -100,000 100,000 200,000 600,000 200,000 -1,600,000 200,000 400,000 -200,000 100,000 300,000 
          inventory impairment charge
                                                                                             
          other contract termination settlements
                                                                                             
          affiliates receivable/payable
                                   62,000 289,000 6,516,000 -96,000 3,000                                                      
          total increase for the year
                                                                                             
          net reductions to revolving credit agreements
                       -19,000,000                    -908,000 1,988,000 -4,195,000                                               
          balance, january 1, 2022
                 5,616,000  5,616,000                                                                      
          cash dividends on class a and class b common stock: 0.1975 per share
                                                                                             
          balance, march 31, 2022
                 5,762,000  5,762,000                                                                      
          balance, june 30, 2022
                                                                                           
          balance, september 30, 2022
                                                                                             
          gain on sale of assets
                                                            -3,100,000        -100,000 -1,800,000 -6,000,000 -500,000 -1,700,000 200,000 -300,000                   
          asset impairment charges
                                                                                             
          net reductions to revolving credit agreement
                                                                                             
          balance, january 1, 2021
                     5,490,000 5,490,000                                                                   
          cash dividends on class a and class b common stock: 0.1925 per share
                                                                                             
          balance, march 31, 2021
                     5,583,000 5,583,000                                                                   
          balance, june 30, 2021
                                                                                           
          balance, september 30, 2021
                                                                                             
          net additions (reductions) to revolving credit agreements
                       2,000,000                  -8,701,000 18,263,000     2,508,000 -3,990,000 -8,665,000 -61,488,000  -12,718,000 7,711,000 38,352,000   -3,479,000 3,199,000    -22,000,000                               
          purchase of equity securities
                                                                                           
          balance, january 1, 2020
                        5,397,000  5,397,000                                                               
          cash dividends on class a and class b common stock: 0.1900 per share
                                                                                             
          balance, march 31, 2020
                        5,453,000  5,453,000                                                               
          balance, june 30, 2020
                                                                                           
          balance, september 30, 2020
                                                                                             
          other asset impairment charges
                                                                                             
          net reduction to revolving credit agreements
                            -5,000,000                                                                 
          balance, january 1, 2019
                            5,352,000   5,352,000                                                           
          cash dividends on class a and class b common stock: 0.1650 per share
                                                                                             
          balance, march 31, 2019
                            5,418,000   5,418,000                                                           
          balance, june 30, 2019
                                                                                            
          balance, september 30, 2019
                                                                                             
          balance, january 1, 2018
                                5,282,000                                                           
          asc 606 adoption
                                                                                             
          asu 2016-01 adoption
                                                                                             
          asu 2018-02 adoption
                                                                                             
          balance, march 31, 2018
                                5,369,000                                                           
          balance, june 30, 2018
                                                                                            
          balance, september 30, 2018
                                                                                             
          income from discontinued operations
                                       493,000                                                      
          income from continuing operations
                                   11,016,000 9,200,000 6,393,000 8,176,000 9,680,000                22,556,000 12,325,000 5,147,000 4,422,000 23,700,000                                  
          adjustments to reconcile income from continuing operations to net cash from operating activities:
                                                                                             
          centennial asset impairment charge
                                                                                            
          net cash from operating activities of continuing operations
                                   15,771,000 20,155,000 26,725,000 -8,029,000 14,187,000                46,082,000 9,541,000 22,468,000 -25,026,000 63,700,000                                  
          net cash from operating activities of discontinued operations
                                                                                           
          net cash from investing activities of continuing operations
                                   -4,965,000 -5,142,000 -6,192,000 -2,088,000 -4,356,000                -31,884,000 -16,135,000 -6,087,000 -6,628,000 -8,200,000                                  
          net cash from investing activities of discontinued operations
                                                                                           
          additions (reductions) to long-term debt
                                                                                             
          cash dividends received from hamilton beach brands holding co.
                                                                                            
          net cash from financing activities of continuing operations
                                   -8,599,000 -11,915,000 -23,984,000 -8,080,000 -2,169,000                1,853,000 899,000 -28,189,000 -11,339,000 -71,300,000                                  
          net cash from financing activities of discontinued operations
                                                                                           
          effect of exchange rate changes on cash of discontinued operations
                                                                                           
          net increase related to discontinued operations
                                                                                             
          net change related to discontinued operations
                                                                                             
          loss from discontinued operations
                                                                                             
          net decrease related to discontinued operations
                                                                                           
          effect of exchange rate changes on cash of continuing operations
                                                       -14,000 -10,000 -4,000 8,000                                   
          adjustments to reconcile from net income to net cash from operating activities:
                                                                                             
          effect of exchange rate changes on cash
                                         -288,000 353,000 -155,000 5,000 -122,000 13,000 8,000 2,000 -40,000 -16,000  -50,000 28,000 -3,000       -3,100,000 3,000,000 -4,200,000 -3,900,000 800,000 3,500,000 -6,100,000 -4,500,000 -3,300,000 1,400,000 3,700,000 200,000 4,900,000 -100,000 200,000 1,700,000 -1,000,000 -300,000 400,000 -500,000 800,000   800,000 500,000 -300,000 -2,000,000 1,900,000 1,400,000 -600,000 -3,000,000 
          decrease for the period
                                         3,783,000 -24,222,000  10,009,000 -1,461,000 -16,781,000  -7,476,000 -9,989,000 -31,823,000  -10,309,000 -9,163,000 -25,320,000  -5,705,000 -11,812,000 -42,985,000    -23,700,000    -12,100,000          -59,100,000    -79,500,000  -6,400,000 -16,800,000 -37,700,000  1,600,000 -29,400,000 -37,600,000  -12,600,000 -5,100,000 -19,000,000 
          working capital changes, excluding the effect of business acquisitions:
                                                                                             
          acquisition of business
                                                           -4,500,000                                 
          financing fees paid
                                                           5,400,000 -5,100,000 -1,700,000               -100,000 200,000   -200,000 -500,000 -4,400,000 -600,000 100,000 -300,000 -800,000 -400,000 -100,000   
          increase for the year
                                                                                             
          proceeds from the sale of property, plant, and equipment
                                            1,717,000                                                 
          centennial long-lived asset impairment charge
                                                                                             
          centennial goodwill impairment charge
                                                                                             
          cash payment for cost method investment
                                                                                             
          decrease for the year
                                                                                             
          net cash from for operating activities
                                                 12,409,000 37,472,000                                           
          reed minerals long-lived asset impairment charge
                                                                                             
          reed minerals goodwill impairment charge
                                                                                             
          proceeds from note receivable
                                                           -100,000 100,000                                 
          cash dividends received from hyster-yale
                                                                                            
          cash in escrow for investment
                                                                                             
          goodwill impairment charge
                                                                                             
          cash in escrow from investment
                                                                                             
          other non-current liabilities
                                                        -1,092,000 171,000 1,289,000 -1,100,000 3,300,000 2,100,000 -3,000,000 -2,000,000 -1,900,000 800,000 -4,500,000 -1,600,000 -16,500,000                         
          proceeds from notes receivable
                                                                                             
          increase related to discontinued operations
                                                                                             
          decrease related to discontinued operations
                                                                                             
          discontinued operations
                                                                                             
          working capital changes, excluding the effect of business acquisition:
                                                                                             
          increase for the period
                                                                   36,700,000 -22,900,000  8,800,000 23,000,000 17,500,000  -16,000,000    -13,700,000               
          restructuring charges
                                                                   -1,900,000 200,000 6,900,000 1,500,000 700,000    600,000    2,400,000     3,200,000   300,000 -300,000 -1,100,000 8,700,000 
          loss on sale of businesses
                                                                                             
          working capital changes, excluding the effect of business dispositions:
                                                                                             
          net cash from operating activities — continuing operations
                                                                   55,000,000 -15,600,000                         
          net cash from operating activities — discontinued operations
                                                                    100,000                         
          proceeds from the sale of businesses
                                                                             1,000,000    -500,000 1,200,000 3,300,000       
          net cash from investing activities — continuing operations
                                                                                             
          net cash from investing activities — discontinued operations
                                                                                             
          restructuring reversal
                                                                                    -200,000         
          net cash from operating activities - continuing operations
                                                                  -8,800,000                           
          net cash from operating activities - discontinued operations
                                                                                             
          operating activities:
                                                                                             
          depreciation and amortization
                                                                                             
          working capital changes
                                                                                             
          investing activities:
                                                                                             
          cash flow before financing activities
                                                                                             
          net cash from financing activities — continuing operations
                                                                   -9,900,000 2,200,000                         
          net cash from financing activities — discontinued operations
                                                                                             
          other liabilities
                                                                    -14,400,000 -3,600,000 -6,500,000 -28,700,000 -40,000,000 16,300,000 -2,500,000 15,300,000 -63,400,000 36,300,000 19,600,000 10,400,000 -53,400,000 27,800,000 15,400,000 4,000,000 -36,300,000         
          goodwill and other intangible assets impairment charges
                                                                                             
          gain on sale of businesses
                                                                             200,000    -200,000 -400,000 -3,700,000         
          non-cash foreign currency
                                                                                             
          adjustments to reconcile net loss to net cash from operating activities:
                                                                                             
          loss on extinguishment of debt
                                                                                           
          minority interest loss
                                                                         -100,000 200,000                   
          extraordinary gain
                                                                                             
          working capital changes, excluding the effect of business acquisitions and dispositions:
                                                                                             
          premium on extinguishment of debt
                                                                                           
          restructuring charge
                                                                          1,700,000    5,000,000               
          minority interest income
                                                                             -100,000 -100,000 -100,000 -500,000 -100,000 100,000 -100,000 -100,000 -300,000 
          restructuring reversals
                                                                                            
          working capital changes, excluding the effect of business acquisitions and dispositions
                                                                                             
          working capital changes, excluding the effect of business dispositions
                                                                                             
          cumulative effect of accounting change
                                                                                             
          accounts payable and other current liabilities
                                                                                             
          additions to long-term debt and revolving credit agreements
                                                                                     -13,600,000   21,500,000 -1,200,000 37,300,000 30,100,000 23,700,000 
          reductions of long-term debt and revolving credit agreements
                                                                                     -10,200,000   -6,300,000 -23,600,000 -8,000,000 -4,200,000 -42,900,000 
          working capital changes, net of dispositions of businesses
                                                                                             
          accounts payable and other liabilities
                                                                                      23,500,000 -23,300,000 8,100,000  5,400,000 5,600,000 20,600,000 
          other-net
                                                                                         700,000    
          additions to long—term debt and revolving credit agreements
                                                                                             
          reductions of long—term debt and revolving credit agreements
                                                                                             
          extraordinary loss
                                                                                             
          proceeds from other unconsolidated affiliates
                                                                                             
          reduction in cash as a result of the deconsolidation of the project mining subsidiaries effective january 1, 2002
                                                                                             
          cumulative effect of accounting change, net-of-tax
                                                                                             
          other non-cash items
                                                                                            500,000 
          other - net
                                                                                            100,000