Investments in debt and equity securities - Schedule of Gross Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]
Gains	$ 3,913	$ 5,839
Losses	7,527	5,895
Municipal
Debt Securities, Available-for-sale [Line Items]
Gains	6	5
Losses	14	23
Corporate
Debt Securities, Available-for-sale [Line Items]
Gains	833	1,646
Losses	3,337	2,596
Foreign
Debt Securities, Available-for-sale [Line Items]
Gains	2,814	3,645
Losses	3,846	3,149
U.S. Treasury Bonds
Debt Securities, Available-for-sale [Line Items]
Gains	260	543
Losses	$ 330	$ 127