Derivatives and hedging activities - Cumulative Basis Adjustment for Fair Value Hedges (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Derivatives, Fair Value [Line Items]
Amortized Amount of the Hedged Assets/(Liabilities)	$ 18,964	$ 22,196
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Available-for-sale Securities, Debt Securities		Available-for-sale Securities, Debt Securities
Fair value hedges | Derivatives designated as hedging instruments | Interest Rate Swaps
Derivatives, Fair Value [Line Items]
Amortized Amount of the Hedged Assets/(Liabilities)	$ 100,000
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Assets/(Liabilities)	1,986
Amortized Cost Basis Amount of the Hedged Assets	146,100
Amounts of designated hedged items	$ 138,600