CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
FPU's
Cantor purchase of Cantor units from Newmark Holdings upon redemption/exchange of FPU's (in shares)	422,646		422,646
Cantor | FPU's | Related Party
Cantor purchase of Cantor units from Newmark Holdings upon redemption/exchange of FPU's (in shares)		208,276		208,276
Common Stock
Dividends declared per share of common stock (in dollars per share)	$ 0.03	$ 0.03	$ 0.06	$ 0.06
Dividends declared and paid per share of common stock (in dollars per share)	$ 0.03	$ 0.03	$ 0.06	$ 0.04
Class A Common Stock
Treasury stock repurchases (in shares)	2,354,217	11,370,647	2,354,217	13,053,518
Class A Common Stock | Common Stock
Grant of exchangeability, redemption and issuance of limited partnership interests and issuance of common stock (in shares)	1,446,005	2,715,924	4,204,210	4,783,787
Treasury stock repurchases (in shares)	2,354,217	11,370,647	2,354,217	13,053,518