Summary of Provision for Income Taxes from Continuing Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current income taxes (benefit)
Federal	$ 1,279	$ (109,240)	$ (2,158)
State	(3,933)	876	(514)
Current Income Tax Expense (Benefit), Total	(2,654)	(108,364)	(2,672)
Deferred income taxes (benefit)
Federal	(80,529)	67,999	(68,488)
State	(4,972)	(2,486)	(14,734)
Deferred Income Tax Expense (Benefit), Total	(85,501)	65,513	(83,222)
Income tax benefit	$ (88,155)	$ (42,851)	$ (85,894)