Compensation - Units Redeemed in Connection with Issuance of Class A Common Stock (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award
Number of units redeemed (in shares)	2,392,823	43,036,797	2,959,978	43,723,341
BGC Units
Share-based Compensation Arrangement by Share-based Payment Award
Number of units redeemed (in shares)	56,562	11,589,383	91,119	11,635,988
Newmark Units
Share-based Compensation Arrangement by Share-based Payment Award
Number of units redeemed (in shares)	2,336,261	31,447,414	2,868,859	32,087,353