Investments in debt and equity securities - Schedule of Gross Unrealized Losses on Investments and Fair Values of Related Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Dec. 31, 2025
Losses
Less than 12 months	$ 1,199	$ 413
More than 12 months	5,508	5,482
Total	6,707	5,895
Fair values
Less than 12 months	133,487	65,164
More than 12 months	154,293	204,302
Total	287,780	269,466
Municipal
Losses
Less than 12 months	2	4
More than 12 months	6	19
Total	8	23
Fair values
Less than 12 months	2,736	2,621
More than 12 months	2,093	5,918
Total	4,829	8,539
Corporate
Losses
Less than 12 months	270	9
More than 12 months	3,100	2,587
Total	3,370	2,596
Fair values
Less than 12 months	34,010	10,284
More than 12 months	62,462	71,989
Total	96,472	82,273
Foreign
Losses
Less than 12 months	391	364
More than 12 months	2,268	2,785
Total	2,659	3,149
Fair values
Less than 12 months	53,133	43,539
More than 12 months	83,948	119,970
Total	137,081	163,509
U.S. Treasury Bonds
Losses
Less than 12 months	536	36
More than 12 months	134	91
Total	670	127
Fair values
Less than 12 months	43,608	8,720
More than 12 months	5,790	6,425
Total	$ 49,398	$ 15,145

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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