Income taxes - Schedule of Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amount
U.S. federal statutory income tax	$ 9,497	$ 47,176	$ 35,491
U.S. state and local income taxes, net of U.S. federal income tax benefits	3,110	13,585	8,770
Unrecognized tax benefit	180	59	(853)
Valuation allowance	1,054	1,121	517
Non-taxable income	(1,083)	(430)	(580)
Provision to return adjustments	(316)	281	239
Change in state and foreign tax rates	(660)	1,384	238
Foreign tax rate differentials	(285)	(223)	(469)
Excess tax benefits from share-based awards	(471)	(1,542)	(1,008)
Non-Deductible Executive Compensation	1,605	3,956	2,831
Other non-deductible expenses	813	310	838
Total income taxes	$ 13,444	$ 65,677	$ 46,014
Percentage
U.S. federal statutory income tax rate (as a percent)	21.00%	21.00%	21.00%
U.S. state and local income taxes, net of U.S. federal income tax benefits (as a percent)	6.80%	6.00%	5.20%
Unrecognized tax benefits (as a percent)	0.40%	0.00%	(0.50%)
Valuation allowance (as a percent)	2.30%	0.50%	0.30%
Non-taxable income (as a percent)	(2.40%)	(0.20%)	(0.30%)
Provision to return adjustments (as a percent)	(0.70%)	0.10%	0.10%
Change in state and foreign tax rates (as a percent)	(1.40%)	0.60%	0.10%
Foreign tax rate differentials (as a percent)	(0.60%)	(0.10%)	(0.30%)
Excess tax benefits from share-based awards (as a percent)	(1.00%)	(0.70%)	(0.60%)
Non-Deductible Executive Compensation (as a percent)	3.50%	1.80%	1.70%
Other non-deductible expenses (as a percent)	1.60%	0.20%	0.50%
Total income tax expense (as a percent)	29.50%	29.20%	27.20%