Other comprehensive income (loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Before-Tax Amount
Other comprehensive income (loss)	$ 20,143	$ (65,035)	$ (20,665)
Tax Expense (Benefit)
Other comprehensive income (loss)	4,015	(13,439)	(3,896)
Net-of-Tax Amount
Other comprehensive income (loss), net of taxes	16,128	(51,596)	(16,769)
Foreign currency translation adjustments
Before-Tax Amount
Other comprehensive income (loss)	6,407	(18,634)	(298)
Tax Expense (Benefit)
Other comprehensive income (loss)	1,130	(3,695)	381
Net-of-Tax Amount
Other comprehensive income (loss), net of taxes	5,277	(14,939)	(679)
Net unrealized gains and losses on investments
Before-Tax Amount
Change in net unrealized gains and losses on investments	13,242	(44,830)	(17,279)
Reclassification adjustment for realized gains and losses on investments	494	(1,571)	(3,088)
Other comprehensive income (loss)	13,736	(46,401)	(20,367)
Tax Expense (Benefit)
Change in net unrealized gains and losses on investments	2,781	(9,414)	(3,629)
Reclassification adjustment for realized gains and losses on investments	104	(330)	(648)
Other comprehensive income (loss)	2,885	(9,744)	(4,277)
Net-of-Tax Amount
Change in net unrealized gains and losses on investments	10,461	(35,416)	(13,650)
Reclassification adjustment for realized gains and losses on investments	390	(1,241)	(2,440)
Other comprehensive income (loss), net of taxes	$ 10,851	$ (36,657)	$ (16,090)