Compensation - Summary of Outstanding LPUs Held by BGC Employees with Stated Vesting (Detail) - LPUs - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate estimated grant date fair value	$ 184,484	$ 178,873
BGC Holdings LPUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate estimated grant date fair value	42,938	42,754
Newmark Holdings LPUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate estimated grant date fair value	$ 189	$ 235