Investment Securities - Amortized cost and estimated fair value by contractual maturity of debt securities (Details 1) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Available-for-Sale Amortized Cost
Due in one year or less
Due after one year through five years	2,000
Due after five years through ten years	2,000
Due after ten years	1,000
Sub-total	5,000
Amortized cost	18,632	$ 19,974
Available-for-Sale Fair Value
Due in one year or less
Due after one year through five years	1,999
Due after five years through ten years	2,002
Due after ten years	1,007
Sub-total	5,008
Fair Value	18,746	19,968
Held-to-Maturity Amortized Cost
Due in one year or less	372
Due after one year through five years	3,197
Due after five years through ten years	2,005
Due after ten years	955
Sub-total	6,529
Amortized cost	7,806	12,979
Held-to-Maturity Fair Value
Due in one year or less	373
Due after one year through five years	3,272
Due after five years through ten years	2,067
Due after ten years	1,000
Sub-total	6,712
Fair Value	8,029	13,222
Mortgage-backed securities - residential
Available-for-Sale Amortized Cost
Amortized cost	13,632	13,974
Available-for-Sale Fair Value
Fair Value	13,738	14,000
Held-to-Maturity Amortized Cost
Amortized cost	1,277	1,535
Held-to-Maturity Fair Value
Fair Value	$ 1,317	$ 1,574