Fair value - Recurring and non recurring basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale	$ 7,000	$ 5,000
Reported Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans held for sale			$ 7,019	$ 4,983
IRLC			293	271
Forward sales commitment			$ 42	$ 506
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Government Agencies	678	20,615
Mortgage-backed securities	69,907	72,537
Municipals	1,652	1,656
Subordinated debt	10,047	10,277
Loans held for sale	7,019	4,983
IRLC	293	271
Forward sales commitment	42	506
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Subordinated debt	500	500
Fair Value, Measurements, Recurring [Member] | Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
U.S. Government Agencies	678	20,615
Mortgage-backed securities	69,907	72,537
Municipals	1,652	1,656
Subordinated debt	10,547	10,777
Loans held for sale	7,019	4,983
IRLC	293	271
Forward sales commitment	$ 42	$ 506