Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activties
Net loss	$ (2,913,142)	$ (558,353)	$ (641,832)
Adjustments to reconcile net loss to cash provided by operating activities:
Depreciation, depletion and amortization	379,345	418,748	447,704
Amortization of acquired sales contracts, net	(8,811)	(13,187)	(9,457)
Prepaid royalties expensed	8,109	9,698	13,706
Deferred income taxes	(367,210)	25,152	(263,099)
Employee stock-based compensation expense	5,760	9,847	11,790
Gains on disposals and divestitures	(2,270)	(27,512)	(120,321)
Asset impairment and noncash mine closure costs	2,613,345	16,868	220,879
Goodwill impairment	0	0	265,423
Losses from disposed operations resulting from Patriot Coal bankruptcy	116,343	0	0
Amortization relating to financing activities	25,241	17,363	24,789
Net loss resulting from early retirement of debt and debt restructuring	27,910	0	42,921
Changes in:
Receivables	98,212	(8,991)	62,881
Inventories	(6,534)	41,548	44,635
Coal derivative assets and liabilities	973	5,449	3,606
Accounts payable, accrued expenses and other current liabilities	(15,532)	41,680	(78,126)
Asset retirement obligations	16,640	18,288	17,432
Pension, postretirement and other postemployment benefits	4,800	(25,347)	7,284
Other	(27,546)	(4,833)	5,527
Cash provided by (used in) operating activities	(44,367)	(33,582)	55,742
Investing activities
Capital expenditures	(119,024)	(147,286)	(296,984)
Minimum royalty payments	(5,871)	(7,317)	(14,947)
Proceeds from sale-leaseback transactions	0	0	34,919
Proceeds from disposals and divestitures	2,191	62,358	433,453
Purchases of short term investments	(246,735)	(211,929)	(213,726)
Proceeds from sales of short term investments	290,205	205,611	194,537
Proceeds from sale of investments in equity investments and securities	2,259	9,464	0
Investments in and advances to affiliates, net	(11,502)	(16,657)	(15,260)
Withdrawals (deposits) of restricted cash	(91,864)	(5,678)	3,453
Cash provided by (used in) investing activities	(180,341)	(111,434)	125,445
Financing activities
Proceeds from term loan	0	0	294,000
Proceeds from issuance of senior notes	0	0	350,000
Payments to retire debt	0	(300)	(628,660)
Payments on term loan	(19,500)	(19,500)	(17,250)
Net payments on other debt	(11,332)	(5,395)	(6,836)
Debt financing costs	0	(4,519)	(20,489)
Dividends paid	0	(2,123)	(25,475)
Expenses related to debt restructuring	(27,910)	0	0
Other	0	(15)	0
Cash used in financing activities	(58,742)	(31,852)	(54,710)
Increase (decrease) in cash and cash equivalents	(283,450)	(176,868)	126,477
Cash and cash equivalents, beginning of period	734,231	911,099	784,622
Cash and cash equivalents, end of period	450,781	734,231	911,099
SUPPLEMENTAL CASH FLOW INFORMATION
Cash paid during the year for interest	283,337	361,727	380,389
Cash refunded during the year for income taxes, net	$ 4,138	$ 4,896	$ 18,741