Investments - Summary of maturities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Held to Maturity, Amortized Cost
After one year, but within five	$ 5,467
After five years, but within ten	13,681
After ten Years	33,821
Total	52,969
Held to Maturity, Approximate Fair Value
After one year, but within five	5,620
After five years, but within ten	13,889
After ten Years	34,414
Total	53,923	$ 55,871
Available for sale, Amortized Cost
After one year, but within five	23,101
After five years, but within ten	12,310
After ten Years	32,196
Total	67,607
Available for sale, Fair Value
After one year, but within five	23,085
After five years, but within ten	12,305
After ten Years	31,871
Fair Value	67,261
Carrying value of investment securities pledged	$ 113,661