Consolidated Statements Of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements Of Operations [Abstract]
Oil and gas production revenues	$ 146,613	$ 166,500
Costs, operating expenses and other:
Lease operating	26,905	32,407
Exploration	389
General and administrative	17,956	9,736
Depreciation, depletion and amortization	84,906	79,320
Impairment of oil and gas properties	1,202
Accretion of asset retirement obligation	3,804	3,664
Drilling interruption costs		18,498
(Gain) loss on abandonment	(364)	1,269
Total operating expenses	134,798	144,894
Income from operations	11,815	21,606
Other income (expense):
Interest income	40	57
Interest expense, net	(73,854)	(75,485)
Derivative expense	(58,971)	(50,262)
Total other non operating income (expenses)	(132,785)	(125,690)
Loss before income taxes	(120,970)	(104,084)
Deferred income tax expense	(10,551)	(9,142)
Net loss	(131,521)	(113,226)
Less income attributable to the redeemable noncontrolling interest	(7,379)	(3,563)
Less convertible preferred stock dividends	(6,179)	(2,758)
Net loss attributable to common shareholders	$ (145,079)	$ (119,547)
Net loss per share attributable to common shareholders:
Basic	$ (2.83)	$ (2.34)
Diluted	$ (2.83)	$ (2.34)
Weighted average number of common shares:
Basic	51,328	51,020
Diluted	51,328	51,020