Investment securities available for sale - Summary of investment securities available for sale having fair value and unrealized loss position (Details) - USD ($)	Jun. 30, 2023	Dec. 31, 2022
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position for less than 12 Months, Fair Value	$ 15,066,000	$ 63,242,000
Securities in a loss position for less than 12 Months, Unrealized Losses	(459,000)	(4,809,000)
Securities in a loss position for more than 12 Months, Fair Value	113,886,000	63,361,000
Securities in a loss Position for more than 12 Months, Unrealized Losses	(12,751,000)	(8,981,000)
Total Fair Value	128,952,000	126,603,000
Total Unrealized Losses	(13,210,000)	(13,790,000)
U.S. Government agencies obligations
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position for less than 12 Months, Fair Value	3,699,000	21,848,000
Securities in a loss position for less than 12 Months, Unrealized Losses	(39,000)	(723,000)
Securities in a loss position for more than 12 Months, Fair Value	57,419,000	37,256,000
Securities in a loss Position for more than 12 Months, Unrealized Losses	(3,068,000)	(3,011,000)
Total Fair Value	61,118,000	59,104,000
Total Unrealized Losses	(3,107,000)	(3,734,000)
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position for less than 12 Months, Fair Value	8,360,000	36,089,000
Securities in a loss position for less than 12 Months, Unrealized Losses	(177,000)	(3,588,000)
Securities in a loss position for more than 12 Months, Fair Value	49,516,000	22,549,000
Securities in a loss Position for more than 12 Months, Unrealized Losses	(8,066,000)	(5,009,000)
Total Fair Value	57,876,000	58,638,000
Total Unrealized Losses	(8,243,000)	(8,597,000)
Municipals
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position for more than 12 Months, Fair Value	1,667,000	1,549,000
Securities in a loss Position for more than 12 Months, Unrealized Losses	(599,000)	(718,000)
Total Fair Value	1,667,000	1,549,000
Total Unrealized Losses	(599,000)	(718,000)
Subordinated debt
Schedule of Available-for-sale Securities [Line Items]
Securities in a loss position for less than 12 Months, Fair Value	3,007,000	5,305,000
Securities in a loss position for less than 12 Months, Unrealized Losses	(243,000)	(498,000)
Securities in a loss position for more than 12 Months, Fair Value	5,284,000	2,007,000
Securities in a loss Position for more than 12 Months, Unrealized Losses	(1,018,000)	(243,000)
Total Fair Value	8,291,000	7,312,000
Total Unrealized Losses	$ (1,261,000)	$ (741,000)