CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities:
Net loss	$ (590,586)	$ (1,090,915)	$ (189,543)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	220,079	281,688	340,006
Write-down of oil and gas properties	357,431	1,362,447	351,192
Accretion expense	40,229	25,988	28,411
Deferred income tax provision (benefit)	13,080	(272,311)	(102,177)
Settlement of asset retirement obligations	(20,514)	(72,382)	(56,409)
Non-cash stock compensation expense	8,443	12,324	11,325
Excess tax benefits	0	(1,586)	0
Non-cash derivative expense (income)	1,471	16,440	(18,028)
Non-cash interest expense	18,404	17,788	16,661
Non-cash reorganization items	8,332	0	0
Other non-cash expense	6,248	0	0
Change in current income taxes	20,088	(37,377)	158
(Increase) decrease in accounts receivable	(1,412)	43,724	51,611
(Increase) decrease in other current assets	(3,493)	1,767	(6,244)
Decrease in inventory	0	1,304	0
Increase (decrease) in accounts payable	1,026	(14,582)	(3,419)
Increase (decrease) in other current liabilities	9,897	(25,936)	(19,152)
Other	(10,135)	(907)	(3,251)
Net cash provided by operating activities	78,588	247,474	401,141
Cash flows from investing activities:
Investment in oil and gas properties	(237,952)	(522,047)	(927,247)
Proceeds from sale of oil and gas properties, net of expenses	0	22,839	242,914
Investment in fixed and other assets	(1,266)	(1,549)	(10,182)
Change in restricted funds	1,046	179,467	(178,072)
Net cash used in investing activities	(238,172)	(321,290)	(872,587)
Cash flows from financing activities:
Proceeds from bank borrowings	477,000	5,000	0
Repayments of bank borrowings	(135,500)	(5,000)	0
Proceeds from building loan	0	11,770	0
Repayments of building loan	(423)	0	0
Net proceeds from issuance of common stock	0	0	225,999
Deferred financing costs	(900)	(68)	(3,371)
Excess tax benefits	0	1,586	0
Net payments for share-based compensation	(762)	(3,127)	(7,182)
Net cash provided by financing activities	339,415	10,161	215,446
Effect of exchange rate changes on cash	(9)	(74)	(736)
Net change in cash and cash equivalents	179,822	(63,729)	(256,736)
Cash and cash equivalents, beginning of year	10,759	74,488	331,224
Cash and cash equivalents, end of year	190,581	10,759	74,488
Supplemental cash flow information:
Cash paid for interest, net of amount capitalized	(32,130)	(34,394)	(14,076)
Cash (paid) refunded for income taxes	$ 25,762	$ 7,212	$ (1)