Securities (Details 3) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Held-to-maturity Securities, Amortized Cost Basis [Abstract]
Due within one year	$ 17,073
Due after one year through five years	96,728
Due after five years through ten years	214,256
Due after ten years	130,343
Held-to-maturity Securities, Fair Value [Abstract]
Due within one year	17,255
Due after one year through five years	98,992
Due after five years through ten years	219,865
Due after ten years	137,641
Available-for-sale Securities, Amortized Cost Basis [Abstract]
Due within one year	0
Due after one year through five years	6,093
Due after five years through ten years	0
Due after ten years	24,770
Available-for-sale Securities, Fair Value [Abstract]
Due within one year	0
Due after one year through five years	6,200
Due after five years through ten years	0
Due after ten years	19,469
Held to Maturity Amortized Cost	458,400	$ 430,163
Fair Value, Held to Maturity	473,753	442,488
Amortized Cost	647,658	724	$ 9,130
Securities available for sale, at fair value	646,805	553,584
Other debt securities
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	18,899
Securities available for sale, at fair value	19,333	17,930
Other equity securities
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	2,500
Securities available for sale, at fair value	4,340	3,599
Government agency mortgage backed securities | Residential mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	362,669
Securities available for sale, at fair value	364,540	296,359
Government agency mortgage backed securities | Commercial mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	58,864
Securities available for sale, at fair value	59,759	47,185
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	168,916
Securities available for sale, at fair value	168,060	157,436
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available-for-sale Securities, Fair Value [Abstract]
Held to Maturity Amortized Cost	0
Fair Value, Held to Maturity	0
Amortized Cost	4,947
Securities available for sale, at fair value	$ 5,104	$ 5,172