Income taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current income tax expense:
Federal	$ 37,723	$ 57,274	$ 47,778
State	3,051	7,600	3,235
Foreign	9,797	16,508	7,567
Current income tax expense:	50,571	81,382	58,580
Deferred income tax expense (benefit):
Federal	(4,025)	13,175	(10,429)
State	254	2,197	388
Foreign	4,064	(2,765)	294
Deferred income tax expense (benefit):	293	12,607	(9,747)
Total income tax expense	$ 50,864	$ 93,989	$ 48,833