Related Party Transactions - Other Agreements with Cantor (Details)			3 Months Ended		6 Months Ended
	Jul. 01, 2023 shares	Jun. 05, 2015 shares	Jun. 30, 2024 USD ($) shares	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) shares	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Aug. 31, 2013 USD ($)
Related Party Transaction [Line Items]
Repurchase agreements | $			$ 6,581,000		$ 6,581,000		$ 0
Reverse repurchase agreements | $			0		0		0
Commissions | $			$ 395,081,000	$ 348,720,000	$ 810,253,000	$ 726,008,000
Limited partnership interest, conversion ratio		1
Conversion of stock, shares converted (in shares) | shares	64,000,000
Minimum number of shares required to be issued (in shares) | shares	75,000,000.0
Class B Common Stock | Cantor
Related Party Transaction [Line Items]
Investment owned, balance (in shares) | shares			93,300,000		93,300,000
Class B Common Stock | CFGM
Related Party Transaction [Line Items]
Investment owned, balance (in shares) | shares			3,000,000.0		3,000,000.0
Class A Common Stock | Cantor
Related Party Transaction [Line Items]
Investment owned, balance (in shares) | shares			0		0
Class A Common Stock | CFGM
Related Party Transaction [Line Items]
Investment owned, balance (in shares) | shares			0		0
Related Party
Related Party Transaction [Line Items]
Repurchase agreements | $			$ 6,600,000		$ 6,600,000		0
Reverse repurchase agreements | $			0		0		$ 0
Recognition of share of FX gains | $			1,400,000	(3,500,000)	1,400,000	(4,900,000)
Commissions | $			$ 100,000	$ 0	$ 200,000	$ 0
Investment authorization in asset-backed commercial paper program | $								$ 350,000,000.0
Right to exchange from Class A to Class B common stock (up to) (in shares) | shares		34,600,000
Related Party | Maximum
Related Party Transaction [Line Items]
Right to exchange from Class A to Class B common stock (up to) (in shares) | shares		34,600,000