Schedule I - Parent Company Only - Organization and Basis of Presentation - Additional Information (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Description Of Business [Line Items]
Dividends declared per share to BGC Class A and Class B common stockholders (in dollars per share)	$ 0.04	$ 0.04	$ 0.04
Dividends paid per share to BGC Class A and Class B common stockholders (in dollars per share)	0.04	0.04	0.04
Parent Company
Description Of Business [Line Items]
Dividends declared per share to BGC Class A and Class B common stockholders (in dollars per share)	0.04	0.04	0.04
Dividends paid per share to BGC Class A and Class B common stockholders (in dollars per share)	$ 0.04	$ 0.04	$ 0.04