Derivatives and hedging activities - Fair Values of Derivative Instruments (Details) $ in Thousands	Jun. 30, 2026 USD ($) security	Dec. 31, 2025 USD ($)
Derivatives, Fair Value
Asset derivatives fair value	$ 14,642	$ 15,896
Liability derivatives fair value	14,462	15,988
Interest rate swaps
Derivatives, Fair Value
Asset derivatives fair value	14,333	15,583
Derivatives designated as hedging instruments \| Other Liabilities.
Derivatives, Fair Value
Liability derivatives fair value	79	329
Derivatives designated as hedging instruments \| Interest rate products \| Other Liabilities.
Derivatives, Fair Value
Notional amount	25,000
Liability derivatives fair value	79	329
Derivatives not designated as hedging instruments \| Other Assets.
Derivatives, Fair Value
Asset derivatives fair value	14,643	15,898
Derivatives not designated as hedging instruments \| Other Liabilities.
Derivatives, Fair Value
Liability derivatives fair value	14,382	15,659
Derivatives not designated as hedging instruments \| Interest rate products \| Other Assets.
Derivatives, Fair Value
Notional amount	417,337	368,500
Asset derivatives fair value	14,642	15,896
Derivatives not designated as hedging instruments \| Interest rate products \| Other Liabilities.
Derivatives, Fair Value
Notional amount	417,337
Liability derivatives fair value	14,382	15,659
Derivatives not designated as hedging instruments \| Other contracts \| Other Assets.
Derivatives, Fair Value
Notional amount	37,109	34,000
Asset derivatives fair value	1	$ 2
Derivatives not designated as hedging instruments \| Other contracts \| Other Liabilities.
Derivatives, Fair Value
Notional amount	$ 6,862
Derivatives not designated as hedging instruments \| Interest rate swaps
Derivatives, Fair Value
Number of instruments held \| security	183
Asset derivatives fair value	$ 454,400
Liability derivatives fair value	$ 424,200

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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