Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Held to Maturity, Amortized Cost
Due within one year	$ 69,290
Due after one year through five years	54,751
Due after five years through ten years	208,703
Due after ten years	149,666
Amortized Cost, Held to Maturity	482,410	412,075
Held to Maturity, Fair Value
Due within one year	69,391
Due after one year through five years	56,469
Due after five years through ten years	204,699
Due after ten years	154,221
Fair Value	484,780	408,576
Available for Sale, Amortized Cost
Due within one year	0
Due after one year through five years	1,075
Due after five years through ten years	5,063
Due after ten years	27,514
Amortized Cost	572,100	513,594
Available for Sale, Fair Value
Due within one year	0
Due after one year through five years	1,146
Due after five years through ten years	4,969
Due after ten years	19,378
Securities available for sale	564,278	501,254
Other debt securities
Available for Sale, Amortized Cost
Amortized Cost	18,918	19,544
Available for Sale, Fair Value
Securities available for sale	19,098	19,554
Other equity securities
Available for Sale, Amortized Cost
Amortized Cost	2,775	2,775
Available for Sale, Fair Value
Securities available for sale	4,470	4,317
Government agency mortgage backed securities | Residential mortgage backed securities:
Available for Sale, Amortized Cost
Amortized Cost	303,024	261,659
Available for Sale, Fair Value
Securities available for sale	302,982	259,992
Government agency mortgage backed securities | Commercial mortgage backed securities:
Available for Sale, Amortized Cost
Amortized Cost	41,063	41,252
Available for Sale, Fair Value
Securities available for sale	42,059	42,041
Government agency collateralized mortgage obligations | Residential mortgage backed securities:
Available for Sale, Amortized Cost
Amortized Cost	168,484	149,682
Available for Sale, Fair Value
Securities available for sale	165,920	146,545
Government agency collateralized mortgage obligations | Commercial mortgage backed securities:
Available for Sale, Amortized Cost
Amortized Cost	4,184	5,007
Available for Sale, Fair Value
Securities available for sale	$ 4,256	$ 5,066