Summary of Significant Accounting Policies - Basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022
Numerator:
Net income	$ 3,350	$ 920	$ 3,823	$ 1,204	$ 4,270	$ 5,027
Less: Income allocated to unvested participating securities	51		65		63	85
Net income available to common shareholders	$ 3,299		$ 3,758		$ 4,207	$ 4,942
Denominator:
Denominator for basic earnings per share - weighted average shares	6,032		5,952		6,030	5,950
Effect of dilutive securities:
Common stock equivalents	0		0		0	0
Denominator for diluted earnings per share - adjusted weighted-average shares and assumed conversions	6,032		5,952		6,030	5,950
Basic earnings per share:
Basic (Dollars per share)	$ 0.55		$ 0.63		$ 0.70	$ 0.83
Diluted earnings per share:
Diluted (Dollars per share)	$ 0.55		$ 0.63		$ 0.70	$ 0.83