Basis of Presentation and Significant Accounting Policies - Additional Information (Details) $ in Thousands		12 Months Ended
	Nov. 01, 2022 reporting_unit	Dec. 31, 2022 USD ($) reporting_unit practice_group	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of practice groups | practice_group		3
Revenue		$ 1,411,979	$ 1,104,925	$ 963,897
Maximum maturity period of investments		3 months
Allowance for doubtful accounts		$ 20,801	16,158	14,894	$ 14,379
Goodwill		819,917	740,743	683,083
Assets		1,879,124	1,627,934
Total stockholders' equity		$ 713,452	704,548	702,620	$ 659,238
Intangible assets amortization period		7 years 7 months 6 days
Number of reporting units | reporting_unit	5	5
Increase (decrease) in the fair value of contingent consideration, net		$ 2,435	2,367	(629)
Unsecured credit facility		600,000
Other income (expense), net
Summary Of Significant Accounting Policies [Line Items]
Increase (decrease) in the fair value of contingent consideration, net		$ (2,400)	(2,400)	600
Performance share units
Summary Of Significant Accounting Policies [Line Items]
Shares vesting term		3 years
Minimum
Summary Of Significant Accounting Policies [Line Items]
Shares vesting term		3 years
Intangible assets amortization period		3 years
Minimum | Capitalized software
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life		3 years
Maximum
Summary Of Significant Accounting Policies [Line Items]
Shares vesting term		4 years
Intangible assets amortization period		15 years
Maximum | Capitalized software
Summary Of Significant Accounting Policies [Line Items]
Property and equipment useful life		5 years
Financial service
Summary Of Significant Accounting Policies [Line Items]
Revenue		$ 235,400	$ 174,800	$ 159,400