Investment Securities (Details 3) (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Dec. 31, 2009
Credit loss portion of other than temporary impairment
Credit-related other-than-temporary impairment	$ (27,575)	$ (27,575)	$ (24,499)
Credit losses on newly identified impairment	0	(3,076)
Non-agency Mortgage-Related Securities [Member]
Credit loss portion of other than temporary impairment
Credit-related other-than-temporary impairment	(17,556)	(17,556)	(17,472)
Credit losses on newly identified impairment	0	(84)
Trust Preferred Debt Securities [Member]
Credit loss portion of other than temporary impairment
Credit-related other-than-temporary impairment	(10,019)	(10,019)	(7,027)
Credit losses on newly identified impairment	$ 0	$ (2,992)