Summary of Significant Accounting Policies - Basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2024	Jun. 30, 2023
Numerator:
Net income	$ 2,501	$ (1,577)	$ 3,350	$ 920	$ 924	$ 4,270
Less: Income allocated to unvested participating securities	78		51		29	63
Net income available to common shareholders	$ 2,423		$ 3,299		$ 895	$ 4,207
Denominator:
Denominator for basic earnings per share - weighted average shares	6,072,000		6,032,000		6,068,000	6,030,000
Effect of dilutive securities:
Common stock equivalents	0		0		0	0
Denominator for diluted earnings per share - adjusted weighted-average shares and assumed conversions	6,072,000		6,032,000		6,068,000	6,030,000
Earnings per share:
Basic (in dollars per share)	$ 0.40		$ 0.55		$ 0.15	$ 0.70
Diluted earnings (loss) per share:
Diluted (in dollars per share)	$ 0.40		$ 0.55		$ 0.15	$ 0.70
Antidilutive securities excluded from computation of earnings per share, amount	0		0		0	0