Condensed Consolidated Statements of Changes in Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Grant of exchangeability and redemption of limited partnership interests, issuance of shares (in shares)	15,974,143	5,064,529	29,118,664	11,707,619
Repurchase of class A common stock (in shares)	9,814,000	8,745,000	10,660,000	8,745,000
Forfeiture of class A common stock (in shares)	200,000	0	200,000	0
Issuance of Class A common stock and RSUs for acquisitions (in shares)		281,230		1,192,907
Cantor purchase of Cantor units from BGC Holdings upon redemption of FPUs (in shares)		480,175	6,368,964	480,175
Equity-based compensation	$ 473	$ 1,690	$ 7,533	$ 7,989
Additional Paid-in Capital
Equity-based compensation	$ 367	$ 1,274	$ 5,741	$ 6,047
Class A Common Stock
Equity-based compensation (in shares)	534,010	589,235	2,630,013	2,570,323
Grant of exchangeability and redemption of limited partnership interests, issuance of shares (in shares)	17,082,000	5,071,000	30,226,000	11,714,000
Issuance of Class A common stock (net of costs) (in shares)	166,280		179,583
Redemption of FPUs (in shares)		556,329		585,717
Repurchase of class A common stock (in shares)	9,813,827	8,745,310	10,659,717	8,745,310
Forfeiture of class A common stock (in shares)	189,726	4,419	238,927	4,419
Issuance of Class A common stock and RSUs for acquisitions (in shares)	3,494,000	274,000	4,152,000	1,186,000
Class A Common Stock | Partnership Units
Issuance of Class A common stock (net of costs) (in shares)		338,503		343,459
Redemption of FPUs (in shares)	133,135		156,049
Class A Common Stock | Smith Mack
Issuance of Class A common stock and RSUs for acquisitions (in shares)	4,432,568		5,090,814