Securities - Contractual Maturities of Securities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Available-for-sale, Amortized Cost
Due in one year or less	$ 72,020
Due after one year through five years	16,778
Due after five years through ten years	236
Total	89,034
Debt maturities without single maturity date	172,225
Available-for-sale, Amortized Cost	261,259		$ 275,379
Available-for-sale, Fair Value
Due in one year or less	72,039
Due after one year through five years	16,811
Due after five years through ten years	246
Total	89,096
Available-for-sale Securities, Debt Maturities, Single Maturity Date, Amortized Cost Basis	89,034
Mortgage-backed securities and collateralized mortgage obligations	173,720
Available-for-sale Securities, Total	262,816		276,021
Held-to-maturity, Amortized Cost
Debt maturities without single maturity date	40,022
Held-to-maturity, Amortized Cost	40,022		42,130
Held-to-maturity, Fair Value
Debt maturities without single maturity date	40,095
Held-to-maturity, Fair Value	40,095		41,996
Proceeds from sale of securities
Proceeds from Sale of Held-to-maturity Securities	0	$ 0
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available-for-sale, Amortized Cost
Available-for-sale, Amortized Cost	122,999		129,752
Available-for-sale, Fair Value
Available-for-sale Securities, Total	124,613		130,705
Held-to-maturity, Amortized Cost
Held-to-maturity, Amortized Cost	14,350		15,002
Held-to-maturity, Fair Value
Held-to-maturity, Fair Value	14,600		15,179
Collateralized Mortgage Backed Securities [Member]
Available-for-sale, Amortized Cost
Available-for-sale, Amortized Cost	49,226		51,569
Available-for-sale, Fair Value
Available-for-sale Securities, Total	49,107		51,329
Held-to-maturity, Amortized Cost
Held-to-maturity, Amortized Cost	25,672		27,128
Held-to-maturity, Fair Value
Held-to-maturity, Fair Value	$ 25,495		$ 26,817