Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Revenues	$ 420,298	$ 644,462	$ 848,404	$ 1,321,467
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	419,042	566,252	838,358	1,128,574
Depreciation, depletion and amortization	58,459	97,372	122,158	202,246
Amortization of acquired sales contracts, net	1	(1,644)	(832)	(5,034)
Change in fair value of coal derivatives and coal trading activities, net	1,158	1,211	2,368	2,431
Asset impairment and mine closure costs	43,701	19,146	129,221	19,146
Selling, general and administrative expenses	19,019	24,268	38,845	46,873
Other operating (income) expense, net	(10,561)	7,403	(12,781)	16,489
Total operating expenses	530,819	714,008	1,117,337	1,410,725
Loss from operations	(110,521)	(69,546)	(268,933)	(89,258)
Interest expense, net
Interest expense (contractual interest of $100,767 and $199,332 for the three and six months ended June 30, 2016)	(45,273)	(99,574)	(89,724)	(198,826)
Interest and investment income	933	962	2,071	3,335
Interest expense, net	(44,340)	(98,612)	(87,653)	(195,491)
Loss before nonoperating expenses	(154,861)	(168,158)	(356,586)	(284,749)
Nonoperating expenses
Expenses related to proposed debt restructuring	0	(4,016)	(2,213)	(4,016)
Reorganization items, net	(21,271)	0	(25,146)	0
Nonoperating income (expense)	(21,271)	(4,016)	(27,359)	(4,016)
Loss before income taxes	(176,132)	(172,174)	(383,945)	(288,765)
Benefit from income taxes	(245)	(4,071)	(1,356)	(7,467)
Net loss	$ (175,887)	$ (168,103)	$ (382,589)	$ (281,298)
Net loss per common share
Basic and diluted LPS - Net loss (usd per share)	$ (8.26)	$ (7.90)	$ (17.97)	$ (13.22)
Basic and diluted weighted average shares outstanding (shares)	21,293	21,291	21,293	21,279