Securities Amortized cost and fair value of securities available for sale by contractual maturity (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Amortized Cost [Abstract]
Due in one year or less	$ 3,801
Due after one year through five years	48,256
Due after five years through ten years	42,227
Due after ten years	19,119
Total	342,233
Fair Value [Abstract]
Due in one year or less	3,838
Due after one year through five years	50,105
Due after five years through ten years	42,035
Due after ten years	19,236
Total	348,263
Mortgage-backed securities [Member]
Amortized Cost [Abstract]
Total	197,492
Fair Value [Abstract]
Total	201,336
Other Asset Backed Securities [Member]
Amortized Cost [Abstract]
Total	31,338
Fair Value [Abstract]
Total	$ 31,713