Stock Transactions and Unit Redemptions - Schedule of Changes in Shares of Common Stock Outstanding (Details) - Class A Common Stock - shares	1 Months Ended				3 Months Ended		12 Months Ended
	Dec. 31, 2023	Nov. 30, 2023	Oct. 31, 2023	Jul. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Stockholders' Equity
Shares outstanding at beginning of period (in shares)						150,384,605	150,384,605	168,272,371	161,175,894
Share issuances:
LPU redemption/exchange (in shares)							3,867,234	4,930,499	6,591,462
Issuance of Class A common stock for Newmark RSUs (in shares)							2,307,339	0
Other (in shares)							(501,694)	(36,596)	18,890,659
Treasury stock repurchases (in shares)	(270,602)	0	(373,260)	(2,787,291)	(2,354,217)	0	(5,785,370)	(24,918,482)	(20,237,430)
Shares outstanding at end of period (in shares)	152,639,359						152,639,359	150,384,605	168,272,371
Restricted Stock Units
Share issuances:
Issuance of Class A common stock for Newmark RSUs (in shares)							2,367,245	2,136,813	1,851,786