Capital and Regulatory Matters - Schedule of Actual and Required Capital Amounts and Ratios (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Capital and Regulatory Matters
Tier-1 Leverage	$ 47,838	$ 43,954
Tier 1 Leverage, ratio (as a percent)	11.39%	10.60%
Common Equity Tier 1	$ 47,838	$ 43,954
Common Equity Tier 1, ratio (as a percent)	18.63%	15.36%
Tier 1	$ 47,838	$ 43,954
Tier 1, ratio (as a percent)	18.63%	15.36%
Total Capital	$ 51,059	$ 47,544
Total Capital, ratio (as a percent)	19.88%	16.62%
Leverage required for capital adequacy purposes	$ 16,798	$ 16,594
Leverage required for capital adequacy purposes, ratio (as a percent)	4.00%	4.00%
Common Equity Tier 1 required for capital adequacy purposes	$ 11,557	$ 12,875
Common Equity Tier 1 required for capital adequacy purposes, ratio (as a percent)	4.50%	4.50%
Tier 1 required for capital adequacy purposes	$ 15,409	$ 17,166
Tier 1 required for capital adequacy purposes, ratio (as a percent)	6.00%	6.00%
Total capital required for capital adequacy purposes	$ 20,545	$ 22,888
Total capital required for capital adequacy purposes, ratio (as a percent)	8.00%	8.00%