Consolidated Statements of Comprehensive Income (Loss) (Unaudited) (USD $) In Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Statement Of Comprehensive (Loss) Income [Abstract]
Net income (loss)	$ 4,477		$ (233,311)		$ 7,800		$ (236,814)
Other comprehensive (loss) income, before tax:
Unrealized gains on securities arising during the period	7,656		41,660		6,964		65,701
Non-credit portion of OTTI losses	(325)		0		(325)		(26,936)
Reclassification of net realized (gains) losses included in net income (loss)	(7,462)		129,749		(11,245)		122,172
Other comprehensive (loss) income on investment securities, before tax	(131)		171,409		(4,606)		160,937
Income tax benefit (expense) related to investment securities	28		(25,712)		711		(24,141)
Other comprehensive (loss) income on investment securities, net of tax	(103)		145,697		(3,895)		136,796
Other comprehensive income on cash flow hedges	554		1,594		1,287		3,152
Other comprehensive income (loss)	451		147,291		(2,608)		139,948
Comprehensive income (loss)	4,928		(86,020)		5,192		(96,866)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Other comprehensive income on investment securities	3,794		36,502		3,794		36,502
Other comprehensive losses on investment securities on which OTTI has been recognized	(276)		(3,563)		(276)		(3,563)
Total other comprehensive income on investment securities	3,518		32,939		3,518		32,939
Other comprehensive loss on cash flow hedge	(1,963)	[1]	(4,472)	[1]	(1,963)	[1]	(4,472)	[1]
Total accumulated other comprehensive income, net of tax	$ 1,555		$ 28,467		$ 1,555		$ 28,467

[1] For the quarter and six month periods ended June 30, 2011 and 2010, other comprehensive loss on cash flow hedges includes $0.8 million and $1.7 million related to a deferred tax asset valuation allowance.