Income Taxes - Summary of components of income tax expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Current income tax (benefit) expense:
Federal	$ 211	$ 89
State	84	157
Total current tax expense	295	246
Deferred income tax benefits:
Federal	198	217
State	84	28
Total deferred tax expense	282	245
Total income tax expense	$ 577	$ 491
Income tax expense statutory rate	21.00%	21.00%