CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Class A Common Stock Common Stock	Class B Common Stock Common Stock
Balance at beginning of period at Dec. 31, 2022	$ 1,524,865	$ 584,709	$ (538,612)	$ 1,145,006	$ (11,989)	$ 343,528	$ 2,011	$ 212
Increase (Decrease) in Stockholders' Equity
Consolidated net income	9,034			6,027		3,007
Foreign currency translation adjustments	(1,895)				(1,460)	(435)
Cantor purchase of Cantor units from Newmark Holdings upon redemption/ exchange of FPUs	1,760					1,760
Dividends to common stockholders	(15,686)			(15,686)
Purchase of limited partnership interests	(21,946)	(3,462)				(18,484)
Earnings distributions to limited partnership interests and other noncontrolling interests	(32,179)					(32,179)
Grant of exchangeability, redemption and issuance of Class A common stock	54,196	39,554				14,580	62
Contributions of capital to and from Cantor for equity-based compensation	(2,437)	(1,902)				(535)
Repurchase of Class A common stock	(32,270)		(26,434)			(5,836)
Restricted stock units compensation	15,054	12,386				2,668
Balance at end of period at Sep. 30, 2023	1,498,496	631,285	(565,046)	1,135,347	(13,449)	308,074	2,073	212
Balance at beginning of period at Jun. 30, 2023	1,495,211	613,847	(549,617)	1,130,645	(5,443)	303,514	2,053	212
Increase (Decrease) in Stockholders' Equity
Consolidated net income	14,153			9,947		4,206
Foreign currency translation adjustments	(9,846)				(8,006)	(1,840)
Dividends to common stockholders	(5,245)			(5,245)
Earnings distributions to limited partnership interests and other noncontrolling interests	(440)					(440)
Grant of exchangeability, redemption and issuance of Class A common stock	19,990	14,385				5,585	20
Contributions of capital to and from Cantor for equity-based compensation	(1,931)	(1,445)				(486)
Repurchase of Class A common stock	(18,909)		(15,429)			(3,480)
Restricted stock units compensation	5,513	4,498				1,015
Balance at end of period at Sep. 30, 2023	1,498,496	631,285	(565,046)	1,135,347	(13,449)	308,074	2,073	212
Balance at beginning of period at Dec. 31, 2023	1,578,682	657,736	(569,235)	1,166,675	(4,555)	325,754	2,095	212
Increase (Decrease) in Stockholders' Equity
Consolidated net income	21,440			15,820		5,620
Foreign currency translation adjustments	5,124				4,096	1,028
Dividends to common stockholders	(15,526)			(15,526)
Purchase of limited partnership interests	(11,284)	(9,066)				(2,218)
Earnings distributions to limited partnership interests and other noncontrolling interests	(14,658)					(14,658)
Grant of exchangeability, redemption and issuance of Class A common stock	109,848	79,300				30,444	104
Contributions of capital to and from Cantor for equity-based compensation	(21,108)	(16,960)				(4,148)
Repurchase of Class A common stock	(182,218)		(146,654)			(35,564)
Forfeiture of Class A common stock	(5,865)	410	(5,134)			(1,141)
Restricted stock units compensation	14,523	11,700				2,823
Balance at end of period at Sep. 30, 2024	1,478,958	723,120	(721,023)	1,166,969	(459)	307,940	2,199	212
Balance at beginning of period at Jun. 30, 2024	1,522,963	703,299	(648,820)	1,154,280	(8,607)	320,434	2,165	212
Increase (Decrease) in Stockholders' Equity
Consolidated net income	24,341			17,794		6,547
Foreign currency translation adjustments	10,186				8,148	2,038
Dividends to common stockholders	(5,105)			(5,105)
Purchase of limited partnership interests	(11,284)	(9,066)				(2,218)
Earnings distributions to limited partnership interests and other noncontrolling interests	(12,358)					(12,358)
Grant of exchangeability, redemption and issuance of Class A common stock	55,726	41,457				14,235	34
Contributions of capital to and from Cantor for equity-based compensation	(20,670)	(16,607)				(4,063)
Repurchase of Class A common stock	(89,550)		(71,949)			(17,601)
Forfeiture of Class A common stock	(316)	0	(254)			(62)
Restricted stock units compensation	5,025	4,037				988
Balance at end of period at Sep. 30, 2024	$ 1,478,958	$ 723,120	$ (721,023)	$ 1,166,969	$ (459)	$ 307,940	$ 2,199	$ 212