Quarterly Selected Financial Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information [Abstract]
Coal Products and Services Revenue	$ 745,192,000	$ 742,180,000	$ 713,776,000	$ 735,971,000	$ 719,386,000	$ 791,269,000	$ 766,332,000	$ 737,370,000	$ 2,937,119,000	$ 3,014,357,000	$ 3,768,126,000
Gross Profit	32,264,000	(5,851,000)	(6,350,000)	(49,842,000)	(44,801,000)	90,000	2,505,000	(18,560,000)
Asset impairment and mine closure costs	17,541,000	5,060,000	1,512,000	0	0	200,397,000	20,482,000	0	24,113,000	220,879,000	539,182,000
Goodwill impairment						0	0	0	0	265,423,000	330,680,000
Asset Impairment Charges					265,423,000
Income (loss) from operations	(5,303,000)	(35,300,000)	(35,805,000)	(73,123,000)	(340,678,000)	(234,753,000)	(36,279,000)	(51,431,000)	(149,531,000)	(663,141,000)	(757,012,000)
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest					(372,794,000)	(207,767,000)	(80,351,000)	(84,316,000)	(558,353,000)	(745,228,000)	(738,915,000)
Income from discontinued operations, including gain on sale - net of tax					1,580,000	79,404,000	8,145,000	14,267,000	0	103,396,000	55,228,000
Net loss	(240,135,000)	(97,218,000)	(96,860,000)	(124,140,000)	(371,214,000)	(128,363,000)	(72,206,000)	(70,049,000)	(558,353,000)	(641,832,000)	(683,687,000)
Income (Loss) from Continuing Operations, Per Diluted Share					$ (1.76)	$ (0.98)	$ (0.38)	$ (0.40)
Earnings Per Share, Diluted	$ (1.13)	$ (0.46)	$ (0.46)	$ (0.59)	$ (1.7498868650)	$ (0.61)	$ (0.34)	$ (0.33)
Increase (decrease) in valuation allowance	$ 169,000,000	$ 15,800,000	$ 18,300,000	$ 23,800,000					$ 226,900,000	$ 8,700,000	$ 31,800,000