CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	$ 0		$ 863	$ 4,025
FPU's
Issuance of Class A common stock for Newmark RSUs (in shares)			208,726
Cantor | FPU's | Affiliated Persons or Entities
Issuance of Class A common stock for Newmark RSUs (in shares)				1,008,731
Common Stock
Dividends declared per share of common stock (in dollars per share)	$ 0.03	$ 0.01	$ 0.09	$ 0.03
Dividends declared and paid per share of common stock (in dollars per share)	$ 0.03	$ 0.01	$ 0.07	$ 0.03
Noncontrolling Interests
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's			$ 863	$ 4,025
Class A Common Stock
Treasury stock repurchases (in shares)	10,163,677	6,307,802	23,217,195	10,800,143
Class A Common Stock | Common Stock
Grant of exchangeability, redemption and issuance of limited partnership interests and issuance of common stock (in shares)	691,844	978,682	5,502,373	24,031,587
Treasury stock repurchases (in shares)	10,163,677	6,307,802	23,217,195	10,800,143