Derivatives and hedging activities - Offsetting Derivatives (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Offsetting of Derivative Assets
Gross Amounts of Recognized Assets	$ 19,833	$ 22,196
Net Amounts of Assets presented in the Balance Sheet	19,833	22,196
Gross Amounts Not Offset presented in the Balance Sheet - Cash Collateral Received	17,590	14,530
Net Amount	2,243	7,666
Offsetting of Derivative Liabilities
Gross Amounts of Recognized Liabilities	20,633	21,466
Net Amounts of Assets presented in the Balance Sheet	20,633	21,466
Gross Amounts Not Offset presented in the Balance Sheet - Financial Instruments	20,633	$ 21,466
Cash collateral paid but not offset	$ 2,450