Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenues	$ 644,462	$ 713,776	$ 1,321,467	$ 1,449,747
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	566,252	622,137	1,128,574	1,308,451
Depreciation, depletion and amortization	97,372	102,464	202,246	206,887
Amortization of acquired sales contracts, net	(1,644)	(3,239)	(5,034)	(6,935)
Change in fair value of coal derivatives and coal trading activities, net	1,211	(2,992)	2,431	(2,078)
Asset impairment and mine closure costs	19,146	1,512	19,146	1,512
Selling, general and administrative expenses	24,268	29,931	46,873	59,067
Other operating (income) expense, net	7,403	(232)	16,489	(8,230)
Total operating expenses	714,008	749,581	1,410,725	1,558,674
Loss from operations	(69,546)	(35,805)	(89,258)	(108,927)
Interest expense, net
Interest expense	(99,574)	(97,960)	(198,826)	(194,431)
Interest and investment income	962	2,036	3,335	3,879
Interest expense, net	(98,612)	(95,924)	(195,491)	(190,552)
Expenses related to debt restructuring	(4,016)	0	(4,016)	0
Loss before income taxes	(172,174)	(131,729)	(288,765)	(299,479)
Benefit from income taxes	(4,071)	(34,869)	(7,467)	(78,480)
Net loss	$ (168,103)	$ (96,860)	$ (281,298)	$ (220,999)
Losses per common share
Basic and diluted LPS (usd per share)	$ (0.79)	$ (0.46)	$ (1.32)	$ (1.04)
Basic and diluted weighted average shares outstanding (shares)	212,914	212,225	212,788	212,198
Dividends declared per common share (usd per share)	$ 0	$ 0	$ 0	$ 0.01