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	629,769						472,849		156,920
Foreign currency translation adjustments	(205)							(98)	(107)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	4,025								4,025
Dividends to common stockholders	(3,693)						(3,693)
Preferred dividend on exchangeable preferred partnership units	0						(6,200)		6,200
Earnings distributions to limited partnership interests and other noncontrolling interests	3,225								3,225
Grant of exchangeability, redemption and issuance of Class A common stock	205,817	96			130,743				74,978
Contributions of capital to and from Cantor for equity-based compensation	(26,290)				(17,980)				(8,310)
Repurchase of Class A common stock	(55,202)					(47,409)			(7,793)
Restricted stock units compensation	7,443				5,904				1,539
Redemption of EPU's	(167,396)								(167,396)
Balance at end of period at Jun. 30, 2021	1,571,220	1,772	212	1,572	506,077	(87,940)	805,720	(2,192)	345,999
Balance at beginning of period at Mar. 31, 2021	970,673	1,695	212	1,572	364,213	(48,221)	372,387	(2,612)	281,427
Increase (Decrease) in Stockholders' Equity
Consolidated net income	585,191						439,744		145,447
Foreign currency translation adjustments	420							420
Dividends to common stockholders	(1,852)						(1,852)
Preferred dividend on exchangeable preferred partnership units	0						(4,559)		4,559
Earnings distributions to limited partnership interests and other noncontrolling interests	7,238								7,238
Grant of exchangeability, redemption and issuance of Class A common stock	191,247	77			119,275				71,895
Contributions of capital to and from Cantor for equity-based compensation	(27,171)				18,742				(8,429)
Repurchase of Class A common stock	(45,919)					(39,719)			(6,200)
Restricted stock units compensation	4,447				3,847				600
Redemption of EPU's	(167,396)								(167,396)
Balance at end of period at Jun. 30, 2021	1,571,220	1,772	212	1,572	506,077	(87,940)	805,720	(2,192)	345,999
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	62,508						48,881		13,627
Foreign currency translation adjustments	(7,591)							(6,385)	(1,206)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	863								863
Dividends to common stockholders	(7,395)						(7,395)
Earnings distributions to limited partnership interests and other noncontrolling interests	(59,906)								(59,906)
Grant of exchangeability, redemption and issuance of Class A common stock	38,301	48			30,994				7,259
Contributions of capital to and from Cantor for equity-based compensation	1,324				1,089				235
Repurchase of Class A common stock	(175,928)					(150,270)			(25,658)
Restricted stock units compensation	4,631				3,974				657
Balance at end of period at Jun. 30, 2022	1,521,000	1,988	212	1,572	523,504	(440,444)	1,121,147	(9,116)	322,137
Balance at beginning of period at Mar. 31, 2022	1,617,862	1,960	212	1,572	497,489	(316,708)	1,078,130	(2,975)	358,182
Increase (Decrease) in Stockholders' Equity
Consolidated net income	61,792						48,519		13,273
Foreign currency translation adjustments	(7,279)							(6,141)	(1,138)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPU's	863								863
Dividends to common stockholders	(5,502)						(5,502)
Earnings distributions to limited partnership interests and other noncontrolling interests	(33,861)								(33,861)
Grant of exchangeability, redemption and issuance of Class A common stock	28,356	28			22,785				5,543
Contributions of capital to and from Cantor for equity-based compensation	3,154				2,675				479
Repurchase of Class A common stock	(145,035)					(123,736)			(21,299)
Restricted stock units compensation	650				555				95
Balance at end of period at Jun. 30, 2022	$ 1,521,000	$ 1,988	$ 212	$ 1,572	$ 523,504	$ (440,444)	$ 1,121,147	$ (9,116)	$ 322,137