Securities (Details 3) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Held-to-maturity Securities [Abstract]
Amortized Cost, Held to Maturity, Due within one year	$ 34,535
Amortized Cost, Held to Maturity, Due after one year through five years	52,911
Amortized Cost, Held to Maturity, Due after five years through ten years	196,982
Amortized Cost, Held to Maturity, Due after ten years	155,627
Amortized Cost, Held to Maturity	440,055	317,766
Fair Value, Held to Maturity, Due within one year	34,604
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	0
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Fair Value	0
Fair Value, Held to Maturity, Due after one year through five years	54,378
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Amortized Cost Basis	1,084
Available-for-sale Securities, Debt Maturities, Year Two Through Five, Fair Value	1,161
Fair Value, Held to Maturity, Due after five years through ten years	191,821
Fair Value, Held to Maturity, Due after ten years	157,211
Fair Value, Held to Maturity	438,014	334,475
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale, Due after five years through ten years	5,067
Amortized Cost, Available for Sale, Due after ten years	27,629
Amortized Cost, Available for Sale	475,814	357,633
Fair Value, Available for Sale, Due after five years through ten years	4,925
Fair Value, Available for Sale, Due after ten years	16,753
Securities available for sale	464,733	356,311
Other debt securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	20,174	22,079
Securities available for sale	20,241	22,930
Equity Securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	2,775	2,355
Securities available for sale	3,877	3,068
Government agency mortgage backed securities [Member] | Residential mortgage backed securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	221,276	139,699
Securities available for sale	220,930	144,817
Government agency mortgage backed securities [Member] | Commercial mortgage backed securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	41,440	41,981
Securities available for sale	42,379	45,058
Government agency collateralized mortgage obligations [Member] | Residential mortgage backed securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	151,340	115,647
Securities available for sale	149,356	117,521
Government agency collateralized mortgage obligations [Member] | Commercial mortgage backed securities [Member]
Available for Sale Securities [Abstract]
Amortized Cost, Available for Sale	5,029	5,091
Securities available for sale	$ 5,111	$ 5,407