Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Amortized Cost
Due within one year	$ 10,976
Due after one year through five years	51,890
Due after five years through ten years	232,081
Due after ten years	139,758
Amortized Cost, Held to Maturity	434,705	412,075
Fair Value
Due within one year	11,093
Due after one year through five years	53,654
Due after five years through ten years	232,491
Due after ten years	147,688
Fair Value	444,926	408,576
Amortized Cost
Due within one year	0
Due after one year through five years	1,067
Due after five years through ten years	5,059
Due after ten years	26,738
Amortized Cost	550,466	513,594
Amortized Cost	550,466
Fair Value
Due within one year	0
Due after one year through five years	1,141
Due after five years through ten years	4,972
Due after ten years	19,573
Securities available for sale	545,623	501,254
Other debt securities
Amortized Cost
Amortized Cost	18,044	19,544
Fair Value
Securities available for sale	18,389	19,554
Other equity securities
Amortized Cost
Amortized Cost	2,331	2,775
Other equity securities	2,331
Fair Value
Securities available for sale	3,479	4,317
Government agency mortgage backed securities | Residential mortgage backed securities:
Amortized Cost
Amortized Cost	289,008	261,659
Fair Value
Securities available for sale	290,684	259,992
Government agency mortgage backed securities | Commercial mortgage backed securities:
Amortized Cost
Amortized Cost	45,938	41,252
Fair Value
Securities available for sale	47,087	42,041
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Amortized Cost
Amortized Cost	157,135	149,682
Fair Value
Securities available for sale	154,972	146,545
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Amortized Cost
Amortized Cost	5,146	5,007
Fair Value
Securities available for sale	$ 5,326	$ 5,066