Investment Securities, Contract Maturity (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Amortized Cost [Abstract]
Within One Year	$ 26,719
After One Year Through Five Years	39,547
After Five Years Through Ten Years	3,256
After Ten Years	0
Amortized cost, before single maturity date	69,522
Investment Securities Not Due at a Single Maturity Date - Mortgage-backed Securities	331,434
Amortized cost, Total	400,956
Fair/Book Value [Abstract]
Within One Year	26,793
After One Year Through Five Years	39,837
After Five Years Through Ten Years	3,383
After Ten Years	0
Fair/Book Value, before single maturity date	70,013
Investment Securities Not Due at a Single Maturity Date - Mortgage-backed Securities	329,730
Fair/Book Value, Total	399,743	404,639	515,573
Amortized Cost [Abstract]
Within One Year	2,211
After One Year Through Five Years	19,482
After Five Years Through Ten Years	23,727
After Ten Years	20,231
Amortized cost, before single maturity date	65,651
Investment Securities Not Due at a Single Maturity Date - Mortgage-backed Securities	4
Amortized cost, Total	65,655	68,505	67,708
Fair Value [Abstract]
Within One Year	2,224
After One Year Through Five Years	19,830
After Five Years Through Ten Years	24,049
After Ten Years	20,002
Fair/Book Value, before single maturity date	66,105
Investment Securities Not Due at a Single Maturity Date - Mortgage-backed Securities	4
Fair Value	$ 66,109