Related Party Transactions - Service Agreements (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Related Party Transaction [Line Items]
Total revenues	$ 550,761	$ 493,080	$ 1,129,375	$ 1,025,947
Tower Bridge International Services LP \| BGC Partners, Inc.
Related Party Transaction [Line Items]
Company ownership of Tower Bridge			52.00%
Tower Bridge International Services LP \| Cantor
Related Party Transaction [Line Items]
Ownership percentage by noncontrolling owners	48.00%		48.00%
Related Party
Related Party Transaction [Line Items]
Mark-up cost of services			7.50%
Share of net profit (loss) from noncontrolling interest	$ 500	500	$ 700	600
Compensation to leased employees	17,700	16,200	37,100	31,700
Related Party \| Service Agreement with Cantor
Related Party Transaction [Line Items]
Total revenues	4,600	4,100	9,100	8,000
Service charges	$ 25,700	$ 24,200	$ 52,300	$ 48,100

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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