Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Current:
Federal	$ (7,784)	$ 7,784	$ 31,707
State and local	1,522	2,460	3,515
Current income tax (benefit) expense	(6,262)	10,244	35,222
Deferred:
Federal	20,211	(70,978)	(852)
State and local	3,302	(15,034)	(294)
Deferred income tax expense (benefit)	23,513	(86,012)	(1,146)
Income tax (expense) benefit	$ 17,251	$ (75,768)	$ 34,076