Income Taxes (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current:
Federal					$ (310)	$ (108,827)	$ (38,502)
State					15,140	25,545	(38,080)
Total current					14,830	(83,282)	(76,582)
Deferred:
Federal					159,566	260,236	62,874
State					16,626	10,911	42,618
Discontinued operations						(10,736)
Total deferred					176,192	260,411	105,492
Total income tax expense					191,022	177,129	28,910
Less: income tax expense (benefit) on discontinued operations					7,418	16,260	(109,641)
Income tax expense - continuing operations	$ 7,375	$ 131,416	$ 50,818	$ (6,005)	$ 183,604	$ 160,869	$ 138,551