Compensation - Compensation Expense Related to Restricted Stock Unit Held by BGC Employees (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
RSU amortization	$ 39,657	$ 19,467

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