Income Taxes - Deferred tax assets and deferred tax liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Net operating loss carry forwards	$ 321	$ 237
Pre-opening costs	44	70
Stock based compensation	754	505
Allowance for loan loss	1,931	1,509
Unrealized loss on securities available-for-sale		985
Total deferred tax assets	3,050	3,306
Deferred tax liabilities:
Fixed assets	(414)	(64)
Deferred rent	(52)	(48)
Unrealized gain on securities available-for-sale	(154)
Investment in partnership	(352)
Deferred loan fees	(29)	(122)
Total deferred tax liabilities	(1,001)	(234)
Deferred tax asset, net	$ 2,049	$ 3,072