Other comprehensive (loss) income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Before-Tax Amount
Other comprehensive income (loss)	$ (1,916)	$ (25,545)	$ 7,286	$ (49,991)
Tax Expense (Benefit)
Other comprehensive loss	(626)	(4,553)	1,269	(9,536)
Net-of-Tax Amount
Other comprehensive loss	(1,290)	(20,992)	6,017	(40,455)
Net unrealized gains and losses on investments
Before-Tax Amount
Change in net unrealized gains and losses on investments	(7,298)	(16,068)	1,078	(41,256)
Reclassification adjustments for realized gains and losses on investments	280	(148)	396	(382)
Other comprehensive income (loss)	(7,018)	(16,216)	1,474	(41,638)
Tax Expense (Benefit)
Change in net unrealized gains and losses on investments	(1,533)	(3,374)	226	(8,664)
Reclassification adjustments for realized gains and losses on investments	59	(31)	83	(80)
Other comprehensive loss	(1,474)	(3,405)	309	(8,744)
Net-of-Tax Amount
Change in net unrealized gains and losses on investments	(5,765)	(12,694)	852	(32,592)
Reclassification adjustments for realized gains and losses on investments	221	(117)	313	(302)
Other comprehensive loss	(5,544)	(12,811)	1,165	(32,894)
Foreign currency translation adjustments
Before-Tax Amount
Other comprehensive income (loss)	5,102	(9,329)	5,812	(8,353)
Tax Expense (Benefit)
Other comprehensive loss	848	(1,148)	960	(792)
Net-of-Tax Amount
Other comprehensive loss	$ 4,254	$ (8,181)	$ 4,852	$ (7,561)