Other comprehensive (loss) income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Before-Tax Amount
Other comprehensive (loss) income	$ (25,545)	$ 2,508	$ (49,991)	$ (6,914)
Tax Expense (Benefit)
Other comprehensive (loss) income	(4,553)	538	(9,536)	(1,450)
Net-of-Tax Amount
Other comprehensive (loss) income	(20,992)	1,970	(40,455)	(5,464)
Net unrealized gains and losses on investments
Before-Tax Amount
Change in net unrealized gains and losses on investments	(16,068)	1,277	(41,256)	(10,312)
Reclassification adjustments for realized gains and losses on investments	(148)	(529)	(382)	(713)
Other comprehensive (loss) income	(16,216)	748	(41,638)	(11,025)
Tax Expense (Benefit)
Change in net unrealized gains and losses on investments	(3,374)	268	(8,664)	(2,165)
Reclassification adjustments for realized gains and losses on investments	(31)	(111)	(80)	(150)
Other comprehensive (loss) income	(3,405)	157	(8,744)	(2,315)
Net-of-Tax Amount
Change in net unrealized gains and losses on investments	(12,694)	1,009	(32,592)	(8,147)
Reclassification adjustments for realized gains and losses on investments	(117)	(418)	(302)	(563)
Other comprehensive (loss) income	(12,811)	591	(32,894)	(8,710)
Foreign currency translation adjustments
Before-Tax Amount
Other comprehensive (loss) income	(9,329)	1,760	(8,353)	4,111
Tax Expense (Benefit)
Other comprehensive (loss) income	(1,148)	381	(792)	865
Net-of-Tax Amount
Other comprehensive (loss) income	$ (8,181)	$ 1,379	$ (7,561)	$ 3,246