Income Taxes - Summary of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets
Allowance for expected credit losses	$ 2,048	$ 14,676
Accrued vacation and bonus	40,608	30,694
Share-based compensation	14,374	13,522
Notes receivable from employees	12,911	13,333
State net operating loss carryforward	1,125	2,090
Foreign net operating and capital loss carryforward	8,357	9,437
Foreign tax credit carryforward	3,536	0
Deferred compensation	534	240
Operating lease assets	64,482	41,283
Employee benefits obligations	340	2,339
Other, net	4,037	3,701
Total deferred tax assets	152,352	131,315
Deferred tax liabilities
Revenue recognition	(6,779)	(8,351)
Operating lease liabilities	(52,087)	(28,523)
Property and equipment, net	(14,766)	(7,663)
Equity debt discount	(4,214)	(6,623)
Goodwill and intangible assets	(206,105)	(202,842)
Total deferred tax liabilities	(283,951)	(254,002)
Foreign withholding tax	(1,537)	(1,980)
Valuation allowance	(10,315)	(13,300)
Net deferred tax liabilities	$ (143,451)	$ (137,967)