Description of Business and Summary of Significant Accounting Policies (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($) option_to_extend segment	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Aug. 20, 2018
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of reportable business segments | segment	5
Advertising costs	$ 13,000	$ 15,200	$ 18,600
Forgivable loans, forgiveness period, minimum	1 year
Forgivable loans, forgiveness period, maximum	10 years
Definite-lived intangible assets amortization period	12 years 4 months 24 days
Number of option to extend | option_to_extend	1
Aggregate principal amount	$ 316,245	316,250
Convertible Note Due 2023
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Aggregate principal amount	$ 316,245	$ 316,250
Senior Notes | Convertible Note Due 2023
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Interest rate (as a percent)	2.00%			2.00%
Aggregate principal amount	$ 1
Software and Software Development Costs
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful of furniture, equipment and internal use software (in years)	3 years
Minimum
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Definite-lived intangible assets amortization period	2 years
Minimum | Furniture, Equipment, And Internal-Use Software
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful of furniture, equipment and internal use software (in years)	1 year
Maximum
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Definite-lived intangible assets amortization period	15 years
Lessee renewal term	7 years
Maximum | Furniture, Equipment, And Internal-Use Software
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Estimated useful of furniture, equipment and internal use software (in years)	7 years
Non U.S | Geographic Concentration Risk | Consolidated Revenues
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue from the work of professionals	38.00%