Income Taxes - Summary of Net Deferred Tax Assets Included in Statement of Financial Position (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Pre-opening expense	$ 25	$ 42
Organizational costs	30	32
Allowance for loan losses	2,849	2,229
Loans held for sale	16	433
Stock-based compensation	345	273
Accrued compensation	163	75
Accrued rent	553	590
State taxes	414	410
Net unrealized loss on securities available for sale	230	178
Nonaccrual loan interest income	55	48
Other	44	19
Total deferred tax assets	4,724	4,329
Deferred tax liabilities:
Loan origination costs	(590)	(477)
Depreciation	(394)	(434)
Other	(68)	(35)
Total deferred tax liabilities	(1,052)	(946)
Net deferred tax asset	$ 3,672	$ 3,383