Derivatives and hedging activities - Cumulative Basis Adjustment for Fair Value Hedges (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value
Amortized Amount of the Hedged Assets/(Liabilities)	$ 19,833	$ 22,196
Hedged Asset, Statement of Financial Position [Extensible Enumeration]	Available-for-sale Securities, Debt Securities
Fair value hedges | Derivatives designated as hedging instruments
Derivatives, Fair Value
Amortized Amount of the Hedged Assets/(Liabilities)	$ 194,035
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	1,333
Fair value hedges | Derivatives designated as hedging instruments | Interest rate swaps
Derivatives, Fair Value
Amortized Amount of the Hedged Assets/(Liabilities)	$ 143,573
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Available-for-sale Securities, Debt Securities	Available-for-sale Securities, Debt Securities
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	$ 871
Amortized Cost Basis Amount of the Hedged Assets	143,600
Amounts of designated hedged items	100,000
Fair value hedges | Derivatives designated as hedging instruments | Fixed Rate Loans
Derivatives, Fair Value
Amortized Amount of the Hedged Assets/(Liabilities)	50,462
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	462
Hedged Asset, carrying value	$ 50,000