Available-for-Sale and Other Securities (Details 2) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Total OTTI losses, OTTI losses included in OCI, and OTTI recognized in the income statement for securities evaluated for impairment by debt security debt
Total OTTI recoveries (losses) (unrealized and realized)	$ (5,726)	$ 27,775	$ 5,368	$ 24,568
Unrealized OTTI recognized recoveries (losses) in OCI	4,362	(30,492)	(11,079)	(36,570)
Net impairment losses recognized in earnings	1,364	2,717	5,711	12,002
Alt-A Mortgage-backed [Member]
Total OTTI losses, OTTI losses included in OCI, and OTTI recognized in the income statement for securities evaluated for impairment by debt security debt
Total OTTI recoveries (losses) (unrealized and realized)	(339)	1,112	597	(3,065)
Unrealized OTTI recognized recoveries (losses) in OCI	208	(1,472)	(958)	1,503
Net impairment losses recognized in earnings	131	360	361	1,562
Pooled Trust Preferred [Member]
Total OTTI losses, OTTI losses included in OCI, and OTTI recognized in the income statement for securities evaluated for impairment by debt security debt
Total OTTI recoveries (losses) (unrealized and realized)	(4,497)	18,877	2,334	21,229
Unrealized OTTI recognized recoveries (losses) in OCI	4,293	(19,075)	(5,744)	(24,643)
Net impairment losses recognized in earnings	204	198	3,410	3,414
Private label CMO [Member]
Total OTTI losses, OTTI losses included in OCI, and OTTI recognized in the income statement for securities evaluated for impairment by debt security debt
Total OTTI recoveries (losses) (unrealized and realized)	(890)	7,786	2,437	6,404
Unrealized OTTI recognized recoveries (losses) in OCI	(139)	(9,945)	(4,377)	(13,430)
Net impairment losses recognized in earnings	$ 1,029	$ 2,159	$ 1,940	$ 7,026