Securities Fair Value Option Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	$ 185,674	$ 167,125	$ 205,756
Fair Value Option Securities, Unrealized Gain or Loss	(1,333)	(8,169)	(8,056)
U.S. agency residential mortgage-backed securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	181,205	157,431	203,816
Fair Value Option Securities, Unrealized Gain or Loss	(1,720)	(8,378)	(8,048)
Other debt securities [Member]
Schedule of Fair Value Option Securities [Line Items]
Fair Value Option Securities, Fair Value	4,469	9,694	1,940
Fair Value Option Securities, Unrealized Gain or Loss	$ 387	$ 209	$ (8)