Investment Securities - Summary of maturities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Held to Maturity, Amortized Cost
After one year, but within five	$ 3,145
After five years, but within ten	15,994
After ten Years	34,764
Total	53,903
Held to Maturity, Approximate Fair Value
After one year, but within five	3,239
After five years, but within ten	16,402
After ten Years	35,771
Total	55,412	55,871
Available for sale, Amortized Cost
After one year, but within five	13,120
After five years, but within ten	18,719
After ten Years	34,953
Total	66,792
Available for sale, Fair Value
After one year, but within five	13,100
After five years, but within ten	18,669
After ten Years	34,678
Fair Value	66,447
Carrying value of investment securities pledged	$ 115,882