Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activties
Net loss	$ (281,298)	$ (220,999)
Adjustments to reconcile net loss to cash used in operating activities:
Depreciation, depletion and amortization	202,246	206,887
Amortization of acquired sales contracts, net	(5,034)	(6,935)
Amortization relating to financing activities	12,539	7,757
Prepaid royalties expensed	3,939	3,575
Employee stock-based compensation expense	3,354	5,469
Asset impairment and non-cash mine closure costs	17,242	1,512
Expenses related to debt restructuring	4,016	0
Amortization of premiums on debt securities held	1,010	0
Gains on disposals and divestitures, net	(1,325)	(18,506)
Deferred income taxes	(7,510)	(78,568)
Changes in:
Receivables	12,433	267
Inventories	(33,743)	3,522
Accounts payable, accrued expenses and other current liabilities	(56,419)	10,495
Income taxes, net	(37)	(571)
Other	3,012	7,749
Cash used in operating activities	(125,575)	(78,346)
Investing activities
Capital expenditures	(99,361)	(95,746)
Additions to prepaid royalties	(409)	(3,341)
Proceeds from disposals and divestitures	991	43,245
Purchases of marketable securities	(161,336)	(168,951)
Proceeds from sale or maturity of marketable securities and other investments	157,729	166,018
Investments in and advances to affiliates	(5,138)	(9,501)
Cash used in investing activities	(107,524)	(68,276)
Financing activities
Payments on term loan	(9,750)	(9,750)
Net payments on other debt	(9,826)	(9,390)
Expenses related to debt restructuring	(4,016)	0
Dividends paid	0	(2,123)
Debt financing costs	0	(1,957)
Withdrawals (deposits) of restricted cash	(37,885)	(1,103)
Cash used in financing activities	(61,477)	(24,323)
Decrease in cash and cash equivalents	(294,576)	(170,945)
Cash and cash equivalents, beginning of period	734,231	911,099
Cash and cash equivalents, end of period	$ 439,655	$ 740,154