Acquisitions - Narrative (Details) $ in Thousands				12 Months Ended
	Mar. 10, 2023 USD ($)	May 03, 2022 USD ($)	Apr. 01, 2022 company	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Acquisition
Goodwill				$ 776,547	$ 705,894	$ 657,131
Number of businesses acquired | company			2
Gerald Eve
Business Acquisition
Business combination, consideration transferred	$ 113,015			113,000
Cash	101,152			101,200
Contingent consideration	11,863			11,900
Goodwill	$ 75,638			75,600
Business acquisition, amount deductible for tax				54,800
Business acquisition, aggregate revenue contribution				$ 91,600
2022 Business Acquisitions
Business Acquisition
Business combination, consideration transferred		$ 72,855			72,900
Contingent consideration		7,322			7,300
Goodwill		50,756			50,800
Business acquisition, amount deductible for tax					35,100
Business acquisition, aggregate revenue contribution					17,800
Cash and stock issued at closing		$ 65,533			$ 65,500