Shareholders' Equity and Regulatory Matters - Accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Dec. 31, 2022
Shareholders' Equity and Regulatory Matters
Net unrealized losses on securities	$ (10,417)	$ (10,862)
Net unrecognized losses on defined benefit plan	(14)	(19)
Total accumulated other comprehensive loss	$ (10,431)	$ (10,881)