CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Common Stock Contingent Class A Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Balance at beginning of period at Dec. 31, 2020	$ 921,147	$ 1,676	$ 212	$ 1,572	$ 351,450	$ (40,531)	$ 342,764	$ (2,094)	$ 266,098
Increase (Decrease) in Stockholders' Equity
Consolidated net income	793,025						601,398		191,627
Foreign currency translation adjustments	(321)							(198)	(123)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	4,025								4,025
Dividends to common stockholders	(5,694)						(5,694)
Non-Controlling interest in Deskeo	13,464								13,464
Preferred dividend on exchangeable preferred partnership units	0						(6,200)		6,200
Earnings distributions to limited partnership interests and other noncontrolling interests	2,071								2,071
Grant of exchangeability, redemption and issuance of Class A common stock	162,657	231			102,067				60,359
Contributions of capital to and from Cantor for equity-based compensation	28,571				19,784				8,787
Repurchase of Class A common stock	(139,334)					(120,068)			(19,266)
Restricted stock units compensation	11,507				9,414				2,093
Redemption of EPU's	(167,396)								(167,396)
Balance at end of period at Sep. 30, 2021	1,623,722	1,907	212	1,572	482,715	(160,599)	932,268	(2,292)	367,939
Balance at beginning of period at Jun. 30, 2021	1,571,221	1,772	212	1,572	506,077	(87,940)	805,721	(2,192)	345,999
Increase (Decrease) in Stockholders' Equity
Consolidated net income	163,255						128,548		34,707
Foreign currency translation adjustments	(116)							(100)	(16)
Dividends to common stockholders	(2,001)						(2,001)
Non-Controlling interest in Deskeo	13,464								13,464
Earnings distributions to limited partnership interests and other noncontrolling interests	(1,154)								(1,154)
Grant of exchangeability, redemption and issuance of Class A common stock	(43,160)	135			(28,676)				(14,619)
Contributions of capital to and from Cantor for equity-based compensation	2,281				1,804				477
Repurchase of Class A common stock	(84,132)					(72,659)			(11,473)
Restricted stock units compensation	4,064				3,510				554
Balance at end of period at Sep. 30, 2021	1,623,722	1,907	212	1,572	482,715	(160,599)	932,268	(2,292)	367,939
Balance at beginning of period at Dec. 31, 2021	1,664,193	1,940	212	1,572	487,447	(290,174)	1,079,661	(2,731)	386,266
Increase (Decrease) in Stockholders' Equity
Consolidated net income	100,420						76,848		23,572
Foreign currency translation adjustments	(16,474)							(13,178)	(3,296)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	863								863
Dividends to common stockholders	(12,753)						(12,753)
Earnings distributions to limited partnership interests and other noncontrolling interests	(54,024)								(54,024)
Grant of exchangeability, redemption and issuance of Class A common stock	72,238	55			57,022				15,161
Contributions of capital to and from Cantor for equity-based compensation	505				407				98
Repurchase of Class A common stock	(281,193)					(237,206)			(43,987)
Restricted stock units compensation	10,339				8,688				1,651
Balance at end of period at Sep. 30, 2022	1,484,114	1,995	212	1,572	553,564	(527,380)	1,143,756	(15,909)	326,304
Balance at beginning of period at Jun. 30, 2022	1,521,002	1,988	212	1,572	523,504	(440,444)	1,121,150	(9,116)	322,136
Increase (Decrease) in Stockholders' Equity
Consolidated net income	37,910						27,964		9,946
Foreign currency translation adjustments	(8,883)							(6,793)	(2,090)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	0
Dividends to common stockholders	(5,358)						(5,358)
Earnings distributions to limited partnership interests and other noncontrolling interests	5,882								5,882
Grant of exchangeability, redemption and issuance of Class A common stock	33,937	7			26,028				7,902
Contributions of capital to and from Cantor for equity-based compensation	(819)				(682)				(137)
Repurchase of Class A common stock	(105,265)					(86,936)			(18,329)
Restricted stock units compensation	5,708				4,714				994
Balance at end of period at Sep. 30, 2022	$ 1,484,114	$ 1,995	$ 212	$ 1,572	$ 553,564	$ (527,380)	$ 1,143,756	$ (15,909)	$ 326,304