Segment Information (Reconciliation Statement Of Segment Income from Operations To Consolidated Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting [Abstract]
Adjusted EBITDAR	$ 81,368		$ 134,805	$ 62,982	$ 261,905
Depreciation, depletion and amortization	(69,423)		(103,965)	(191,581)	(306,211)
Amortization of acquired sales contracts, net	(104)		1,994	728	7,028
Asset impairment and mine closure costs	(46)	$ (129,300)	(2,120,292)	(129,267)	(2,139,438)
Losses from disposed operations resulting from Patriot Coal bankruptcy	0		(149,314)	0	(149,314)
Interest expense, net	(45,582)		(99,087)	(133,235)	(294,578)
Expenses related to proposed debt restructuring	0		(7,482)	(2,213)	(11,498)
Reorganization items, net	(20,904)		0	(46,050)	0
Loss before income taxes	$ (54,691)		$ (2,343,341)	$ (438,636)	$ (2,632,106)