Related Party Transactions - Service Agreements and Loans (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Related Party Transaction
Fees to related parties	$ 6,244	$ 7,301	$ 20,863	$ 20,878
Loans, forgivable loans and other receivables from employees and partners, net	631,776		631,776		$ 500,833
Labor and related expense	400,798	432,991	1,131,336	1,301,078
Cantor Fitzgerald Limited Partnership And B G C Partners Incorporation | Related Party
Related Party Transaction
Fees to related parties	6,200	7,300	20,900	20,900
Employee Loans
Related Party Transaction
Labor and related expense	$ 28,300	$ 21,400	$ 78,700	$ 61,000