CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Thousands	Total	Cantor	Smith Mack	Additional Paid-in Capital	Additional Paid-in Capital Cantor	Additional Paid-in Capital Smith Mack	Treasury Stock	Retained Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest in Subsidiaries	Noncontrolling Interest in Subsidiaries Cantor	Noncontrolling Interest in Subsidiaries Smith Mack	Class A Common Stock Common Stock	Class A Common Stock Common Stock Smith Mack	Class B Common Stock Common Stock
Beginning balance at Dec. 31, 2021	$ 663,315			$ 2,451,135			$ (623,734)	$ (1,171,919)	$ (40,548)	$ 43,563			$ 4,359		$ 459
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	58,867							48,712		10,155
Other comprehensive income (loss), net of tax	(5,668)								(4,883)	(785)
Equity-based compensation	13,946			10,599						3,314			33
Dividends to common stockholders and participating RSU holders	(14,859)							(14,859)		0
Earnings distributions to limited partnership interests and other noncontrolling interests	(7,598)									(7,598)
Grant of exchangeability and redemption of limited partnership interests	122,841		$ 2,710	92,245		$ 2,279				30,286		$ 419	310	$ 12
Issuance of Class A common stock (net of costs)	3,802			3,780						17			5
Redemption of FPUs	(249)									(249)
Repurchase of Class A common stock	(103,888)						(87,507)			(16,381)
Forfeitures of Class A common stock	(262)			(8)			(213)			(41)
Contributions of capital to and from Cantor for equity-based compensation		$ (2,570)			$ (1,946)						$ (624)
Cantor purchase of Cantor units from BGC Holdings upon redemption of FPUs	1,487									1,487
Other	1,334			1,334						0
Ending balance at Dec. 31, 2022	733,208			2,559,418			(711,454)	(1,138,066)	(45,431)	63,563			4,719		459
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	38,775							36,265		2,510
Other comprehensive income (loss), net of tax	7,607								6,849	758
Equity-based compensation	126,738			124,825			8			1,766			139
Dividends to common stockholders and participating RSU holders	(17,381)							(17,381)
Earnings distributions to limited partnership interests and other noncontrolling interests	(28,946)			(16,652)						(12,294)
Grant of exchangeability and redemption of limited partnership interests	113,201			86,505						26,405			291
Issuance of Class A common stock (net of costs)	214			195						14			5
Redemption of FPUs	(702)			(155)						(547)
Repurchase of Class A common stock	(114,580)						(107,889)			(6,691)
Forfeiture of Class A common stock	(1,190)			331			(1,410)			(111)
Contributions of capital to and from Cantor for equity-based compensation	2,782			2,666						116
Issuance of Class A common stock and RSUs for acquisitions			$ 7,275			$ 6,843						$ 377		$ 55
Cantor purchase of Cantor units from BGC Holdings upon redemption of FPUs	11,539									11,539
Redemption of FPUs and issuance of RSUs due to the Corporate Conversion	14,506			12,410						2,096
Cantor units converted into shares of BGC Group Class B common stock due to the Corporate Conversion	0			75,788						(76,428)					640
Restricted stock awards granted upon conversion of limited partnership interests due to the Corporate Conversion	0			(386)									386
Conversion of Class B common stock to Class A common stock	0												4		(4)
Cancellation of BGC Partners Inc. Treasury Stock due to Corporate Conversion	0			(751,768)			753,331						(1,563)
Other	5,110			5,110
Ending balance at Dec. 31, 2023	898,156			2,105,130			(67,414)	(1,119,182)	(38,582)	13,073			4,036		1,095
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	123,228							126,988		(3,760)
Other comprehensive income (loss), net of tax	(21,515)								(21,267)	(248)
Equity-based compensation	170,889			170,731			(36)						194
Dividends to common stockholders and participating RSU holders	(34,165)							(34,165)
Issuance of Class A common stock (net of costs)	(1,239)			(1,242)									3
Repurchase of Class A common stock	(262,211)						(262,211)
Forfeiture of Class A common stock	(1,066)			1,001			(2,067)
Contributions of capital to and from Cantor for equity-based compensation		$ 51,462			$ 51,462
Issuance of Class A common stock and RSUs for acquisitions	8,520			8,509									11
Cantor purchase of Cantor units from BGC Holdings upon redemption of FPUs	171,667									171,667
Other	(24,487)			(24,487)
Ending balance at Dec. 31, 2024	$ 1,079,239			$ 2,311,104			$ (331,728)	$ (1,026,359)	$ (59,849)	$ 180,732			$ 4,244		$ 1,095