Available-for-sale securities - Investment Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	$ 110,056	$ 105,605
Gross Unrealized Gains	0	7
Gross Unrealized (Losses)	(20,869)	(21,092)
Fair Value	89,187	84,520
U. S. Government agency and mortgage-backed securities
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	80,500	73,480
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(14,829)	(14,434)
Fair Value	65,671	59,046
Corporate bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	17,995	19,773
Gross Unrealized Gains	0	7
Gross Unrealized (Losses)	(4,229)	(5,125)
Fair Value	13,766	14,655
Subordinated notes
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	5,000	5,000
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(773)	(398)
Fair Value	4,227	4,602
SBA loan pools
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	6,002	6,791
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(965)	(1,073)
Fair Value	5,037	5,718
Municipal bonds
Debt Securities, Available-for-Sale [Line Items]
Amortized Cost	559	561
Gross Unrealized Gains	0	0
Gross Unrealized (Losses)	(73)	(62)
Fair Value	$ 486	$ 499