Derivatives and hedging activities - Fair Values of Derivative Instruments on the Balance Sheet (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($)
Derivatives, Fair Value
Interest rate floor and swaps	$ 22,196	$ 9,870
Liability Derivatives	21,466	8,818
Cash collateral	14,530
Net Amounts of Assets presented in the Balance Sheet	21,466	8,818
Interest expense
Derivatives, Fair Value
Amount of gain or (loss) reclassified as a increase to interest income		(48)
Interest income
Derivatives, Fair Value
Amount of gain or (loss) reclassified as a increase to interest income	276	607
Interest Rate Floor
Derivatives, Fair Value
Interest rate floor and swaps	1	844
Interest Rate Swaps
Derivatives, Fair Value
Interest rate floor and swaps	21,794	9,026
Credit-risk contract
Derivatives, Fair Value
Cash collateral	7,400	7,400
Net Amounts of Assets presented in the Balance Sheet	2,000	5,600
Derivatives designated as hedging instruments
Derivatives, Fair Value
Interest rate floor and swaps	1	844
Derivatives designated as hedging instruments | Interest Rate Floor
Derivatives, Fair Value
Notional amount	25,000
Interest rate floor and swaps		844
Derivatives designated as hedging instruments | Interest Rate Floor | Other Assets.
Derivatives, Fair Value
Interest rate floor and swaps	1
Derivatives not designated as hedging instruments
Derivatives, Fair Value
Interest rate floor and swaps	22,195	9,026
Liability Derivatives	$ 21,466	8,811
Derivatives not designated as hedging instruments | Interest Rate Swaps
Derivatives, Fair Value
Number of instruments held | security	86
Accrued interest	$ 400	300
Notional amount	382,476	392,700
Derivatives not designated as hedging instruments | Interest Rate Swaps | Other Assets.
Derivatives, Fair Value
Interest rate floor and swaps	22,195	9,026
Derivatives not designated as hedging instruments | Interest Rate Swaps | Other Liabilities.
Derivatives, Fair Value
Liability Derivatives	21,466	$ 8,811
Cash Flow Hedge | Interest income
Derivatives, Fair Value
Amount of gain or (loss) reclassified as a increase to interest income	$ 64