Income taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Current income tax expense:
Federal	$ 5,638	$ 37,723	$ 57,274
State	62	3,051	7,600
Foreign	16,347	9,797	16,508
Current income tax expense:	22,047	50,571	81,382
Deferred income tax expense (benefit):
Federal	(1,919)	(4,025)	13,175
State	107	254	2,197
Foreign	(4,972)	4,064	(2,765)
Deferred income tax expense (benefit):	(6,784)	293	12,607
Total income tax expense	$ 15,263	$ 50,864	$ 93,989