Securities Fair Value Option Securities Part 5 (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	$ 284,296	$ 651,226
Fair Value Option Securities, Unrealized Gain or Loss	4,770	19,251
U.S. Agency Residential Mortgage-backed Securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	257,040	626,109
Fair Value Option Securities, Unrealized Gain or Loss	3,314	19,233
Corporate Debt Securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	26,486	25,117
Fair Value Option Securities, Unrealized Gain or Loss	1,409	18
Other Debt Securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	770	0
Fair Value Option Securities, Unrealized Gain or Loss	$ 47	$ 0