Related Party Transactions - Transactions with Executive Officers and Directors (Details) - USD ($)					1 Months Ended					3 Months Ended				6 Months Ended
	Jun. 02, 2023	May 18, 2023	Aug. 11, 2022	Apr. 01, 2021	Jun. 30, 2023	May 31, 2023	Apr. 30, 2023	Jun. 30, 2022	Apr. 30, 2022	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 08, 2023	Mar. 14, 2022
Related Party Transaction [Line Items]
Repurchase of class A common stock (in shares)					3,428,000	3,300,000	3,086,000	7,595,000	0	9,814,000	846,000	8,745,000	0	10,660,000	8,745,000
Class A Common Stock
Related Party Transaction [Line Items]
Repurchase of class A common stock (in shares)										9,813,827		8,745,310		10,659,717	8,745,310
Stock repurchased, weighted average price (in dollars per share)										$ 4.44		$ 3.36		$ 4.48	$ 3.36
Class A Common Stock | Mr. Merkel
Related Party Transaction [Line Items]
Repurchase of class A common stock (in shares)	150,000
Stock repurchased, weighted average price (in dollars per share)	$ 4.21
Related Party
Related Party Transaction [Line Items]
Shares withheld for tax withholding obligation, price per share (in dollars per share)		$ 4.61
Related Party | Mr. Merkel
Related Party Transaction [Line Items]
Shares withheld for tax withholding obligation, price per share (in dollars per share)		$ 4.61
Related Party | Mr. Lutnick
Related Party Transaction [Line Items]
Determination amount		$ 6,650,000
Related Party | Mr. Windeatt
Related Party Transaction [Line Items]
Number of non-exchangeable LPU-NEWs (in shares)																	135,514
Number of non-exchangeable PLPU (in shares)																	27,826
Average determination price (in dollars per share)																	$ 4.84
Exchange share price (in dollars per share)			$ 4.08
Shares authorized to be repurchased (in shares)			135,514
Number of shares redeemed (in shares)			27,826
Number of shares redeemed, value			$ 134,678
Related Party | Class A Common Stock | Mr. Merkel
Related Party Transaction [Line Items]
Grants in period, net (in shares)		196,525
Related Party | Class A Common Stock | Mr. Lutnick
Related Party Transaction [Line Items]
Grants in period, net (in shares)		5,710,534
Related Party | NPU-CV, PSU-CV & PSU | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period		$ 0
Related Party | NPSU-CV | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		148,146
Related Party | PSU-CV | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		33,585
Related Party | PSU | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		74,896
Related Party | PSU | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period		$ 0
Related Party | NPPSU-CV & PPSU-CV | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period		$ 843,750
Related Party | NPPSU-CV | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		148,146
Determination amount		$ 681,250
Related Party | PPSU-CV | Mr. Merkel
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		33,585
Determination amount		$ 162,500
Related Party | Share-Based Payment Arrangement | Class A Common Stock
Related Party Transaction [Line Items]
Shares granted in period (in shares)										1,000,000
Related Party | Share-Based Payment Arrangement | Class A Common Stock | Mr. Merkel
Related Party Transaction [Line Items]
Shares granted in period (in shares)		256,627
Related Party | Share-Based Payment Arrangement | Class A Common Stock | Mr. Lutnick
Related Party Transaction [Line Items]
Grants in period, net (in shares)		232,610
Related Party | Share-Based Payment Arrangement | Class A Common Stock | Mr. Lutnick | Exchangeable PSU
Related Party Transaction [Line Items]
Shares granted in period (in shares)		520,380
Related Party | Share-Based Payment Arrangement | Class A Common Stock | Mr. Lutnick | Non-exchangeable PSU
Related Party Transaction [Line Items]
Shares granted in period (in shares)		11,332,727
Related Party | Non-exchangeable PSUs & PPSUs | Prior To 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Determination amount		$ 474,195
Related Party | Non-exchangeable PSU | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		11,332,727
Related Party | Non-exchangeable PSU | Prior To 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		7,879,736
Related Party | Non-exchangeable PPSU | Prior To 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		103,763
Related Party | Incrementally Monetized Non-exchangeable PSUs & PPSUs | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period		$ 6,650,000
Related Party | Incrementally Monetized Non-exchangeable PSUs & PPSUs | On 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Determination amount		$ 6,175,805
Related Party | Incrementally Monetized Non-exchangeable PSU | On 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		3,452,991
Related Party | Incrementally Monetized Non-exchangeable PPSU | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		1,451,805
Related Party | Incrementally Monetized Non-exchangeable PPSU | On 5/18/2023 | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		1,348,042
Related Party | Exchangeable PSU | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		520,380
Related Party | Non-exchangeable HDU | Mr. Lutnick
Related Party Transaction [Line Items]
Shares redeemed in period (in shares)		1,474,930
Related Party | Non-exchangeable HDU | Mr. Lutnick | BGC Parnters
Related Party Transaction [Line Items]
Shares redeemed in period		$ 2,100,000
Related Party | Non-exchangeable HDU | Mr. Lutnick | Newmark
Related Party Transaction [Line Items]
Shares redeemed in period		$ 9,148,000
Related Party | Non-exchangeable Limited Partnership Interests | Reporting Person
Related Party Transaction [Line Items]
Shares granted in period (in shares)				128,279
Shares repurchased (in shares)																128,279
Shares repurchased (in dollars per share)																$ 4.79