New accounting standards (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024	Jan. 01, 2024
New accounting standards
Other assets	$ 104,857	$ 102,746
Other liabilities	79,188	77,216
Retained earnings	$ 726,989	$ 687,366
ASU) No. 2023-02 "Investments Equity Method and Joint Ventures (Topic 323) | Adjustment
New accounting standards
Other assets			$ 19,000
Other liabilities			21,000
Retained earnings			$ (1,700)