CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ (480,294)	$ 30,387
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	164,373	175,481
Write-down of oil and gas properties	715,706
Accretion expense	12,817	15,288
Deferred income tax (benefit) provision	(264,954)	18,094
Settlement of asset retirement obligations	(35,923)	(24,915)
Non-cash stock compensation expense	6,028	5,358
Non-cash derivative expense	7,931	2,697
Non-cash interest expense	8,737	8,229
Change in current income taxes	7,206	(6)
(Increase) decrease in accounts receivable	23,047	(25,524)
Increase in other current assets	(1,959)	(82)
Increase (decrease) in accounts payable	(7,826)	1,843
Increase (decrease) in other current liabilities	(8,720)	50,785
Other	(504)	(675)
Net cash (used in) provided by operating activities	145,665	256,960
Cash flows from investing activities:
Investment in oil and gas properties	(264,355)	(517,904)
Proceeds from sale of oil and gas properties, net of expenses	10,100	51,955
Investment in fixed and other assets	(727)	(3,896)
Change in restricted funds	179,475	(356)
Net cash used in investing activities	(75,507)	(470,201)
Cash flows from financing activities:
Proceeds from bank borrowings	5,000
Repayment of bank borrowings	(5,000)
Net proceeds from issuance of common stock		226,036
Deferred financing costs		(3,167)
Net payments for share-based compensation	(3,069)	(6,948)
Net cash provided by (used in) financing activities	(3,069)	215,921
Effect of exchange rate changes on cash	78	(18)
Net change in cash and cash equivalents	67,167	2,662
Cash and cash equivalents, beginning of period	74,488	331,224
Cash and cash equivalents, end of period	$ 141,655	$ 333,886