Income Taxes (Details) (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, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CURRENT:
Federal									$ 612	$ (39,210)	$ (28,797)
State									1,409	1,061	1,268
Total current benefit									2,021	(38,149)	(27,529)
DEFERRED:
Federal									4,162	(1,460)	34,878
State									1,237	(1,858)	2,394
Effect of tax law change										749
Total deferred provision (benefit)									5,399	(2,569)	37,272
Total provision (benefit) for income taxes	$ 2,651	$ 937	$ 4,799	$ (967)	$ (12,593)	$ (17,403)	$ (11,697)	$ 975	$ 7,420	$ (40,718)	$ 9,743