CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	$ 863		$ 863	$ 4,025
FPU's
Issuance of Class A common stock for Newmark RSUs (in shares)			208,276
Cantor | FPU's | Affiliated Persons or Entities
Issuance of Class A common stock for Newmark RSUs (in shares)	208,276			1,008,731
Common Stock
Dividends declared per share of common stock (in dollars per share)	$ 0.03	$ 0.01	$ 0.06	$ 0.02
Dividends declared and paid per share of common stock (in dollars per share)	$ 0.03	$ 0.01	$ 0.04	$ 0.02
Noncontrolling Interests
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	$ 863		$ 863	$ 4,025
Class A Common Stock
Treasury stock repurchases (in shares)	11,370,647	3,613,098	13,053,518	4,492,341
Class A Common Stock | Common Stock
Grant of exchangeability, redemption and issuance of limited partnership interests and issuance of common stock (in shares)	2,715,924	20,235,634	4,783,787	2,827,773,905
Treasury stock repurchases (in shares)	11,370,647	3,613,098	13,053,518	4,492,341