CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating activities
Net loss	$ (50,722)	$ (62,384)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depletion, depreciation and amortization	122,694	69,036
Deferred income taxes	52,646	33,447
Unsuccessful well costs	85,668	19,237
Change in fair value of derivatives	(3,302)	14
Cash settlements on derivatives	(15,144)	(7,081)
Equity-based compensation	37,000	38,851
Other	2,827	4,983
Changes in assets and liabilities:
Decrease in receivables	88,092	155,884
Increase in inventories	(11,927)	(14,075)
Increase in prepaid expenses and other	(3,939)	(1,344)
Decrease in accounts payable	(64,900)	(66,536)
Increase (decrease) in accrued liabilities	37,877	(9,347)
Net cash provided by operating activities	276,870	160,685
Investing activities
Oil and gas assets	(166,581)	(188,075)
Other property	(3,278)	(6,912)
Restricted cash	1,965	793
Net cash used in investing activities	(167,894)	(194,194)
Financing activities
Payment on long-term debt	(100,000)
Purchase of treasury stock	(13,041)	(8,378)
Deferred financing costs	(2,225)	(1,254)
Net cash used in financing activities	(115,266)	(9,632)
Net decrease in cash and cash equivalents	(6,290)	(43,141)
Cash and cash equivalents at beginning of period	515,164	673,092
Cash and cash equivalents at end of period	508,874	629,951
Cash paid for:
Interest	17,198	21,339
Income taxes	$ 28,722	$ 16,620