Compensation - Compensation Expense Related to Restricted Stock Unit Held by BGC Employees (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Compensation Related Costs [Abstract]
RSU, RSU Tax Account, and restricted stock amortization	$ 21,229	$ 4,622	$ 40,696	$ 10,218

Share based compensation arrangement by share based payment award restricted stock units amortization.

No definition available.

Name:	bgcp_ShareBasedCompensationArrangementByShareBasedPaymentAwardRestrictedStockUnitsAmortization
Namespace Prefix:	bgcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration