Securities (Details 3) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Held-to-maturity Securities, Amortized Cost Basis [Abstract]
Due within one year	$ 11,419
Due after one year through five years	110,979
Due after five years through ten years	129,883
Due after ten years	104,001
Held-to-maturity Securities, Fair Value [Abstract]
Due within one year	11,504
Due after one year through five years	114,123
Due after five years through ten years	131,145
Due after ten years	106,121
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Due within one year	0
Due after one year through five years	2,066
Due after five years through ten years	1,047
Due after ten years	23,749
Available-for-sale Securities, Fair Value [Abstract]
Due within one year	0
Due after one year through five years	2,158
Due after five years through ten years	1,039
Due after ten years	18,389
Held to maturity, amortized cost	356,282	$ 458,400
Held to maturity, fair value	362,893	473,753
Amortized Cost	686,405	1,117	$ 724
Securities available for sale, at fair value	674,248	646,805
Other debt securities
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	21,006
Securities available for sale, at fair value	21,106
Other equity securities
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	0
Securities available for sale, at fair value	0	4,340
Government agency mortgage backed securities | Residential mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	414,019
Securities available for sale, at fair value	409,317	364,540
Government agency mortgage backed securities | Commercial mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	50,628
Securities available for sale, at fair value	50,863	59,759
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	171,362
Securities available for sale, at fair value	168,826	168,060
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to maturity, amortized cost	0
Held to maturity, fair value	0
Amortized Cost	2,528
Securities available for sale, at fair value	$ 2,550	$ 5,104