Line of Credit, Maturity Date Extension

No definition available.

Name:	bgcp_LineOfCreditMaturityDateExtension
Namespace Prefix:	bgcp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The average effective interest rate during the reporting period.

+ References

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+ Details

Name:	us-gaap_DebtInstrumentInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

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-Topic 942
-SubTopic 470
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+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the aggregate of total long-term debt, including current maturities and short-term debt.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtLongtermAndShorttermCombinedAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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+ Details

Name:	us-gaap_DeferredFinanceCostsGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

+ References

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Name:	us-gaap_DeferredFinanceCostsNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate amount of interest paid or due on all long-term debt.

+ References

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-Name Regulation S-K (SK)
-Number 229
-Section 1402
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-Paragraph 1
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+ Details

Name:	us-gaap_InterestExpenseLongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of the fee for available but unused credit capacity under the credit facility.

+ References

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Name:	us-gaap_LineOfCreditFacilityCommitmentFeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

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+ Details

Name:	us-gaap_ProceedsFromIssuanceOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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-Paragraph 1
-Subparagraph (SX 210.4-08(f))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480678/235-10-S99-1

+ Details

Name:	us-gaap_RepaymentsOfLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ References

+ Details

Name:	us-gaap_SecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=bgcp_BGCCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=bgcp_UnsecuredCreditAgreementNovemberTwentyEightTwoThousandEighteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=bgcp_SeniorRevolvingCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=bgcp_NewSeniorRevolvingCreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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Notes Payable and Other Borrowings - Narrative (Detail) R$ in Millions									3 Months Ended			6 Months Ended
	Apr. 01, 2024 USD ($)	Mar. 12, 2024 USD ($)	Mar. 08, 2024 USD ($)	Oct. 06, 2023 USD ($)	Sep. 27, 2019 USD ($)	Jul. 24, 2018 USD ($)	Aug. 23, 2017 USD ($)	Aug. 22, 2017 USD ($)	Jun. 30, 2024 USD ($)	Mar. 31, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 10, 2024 USD ($)	Jun. 07, 2024 USD ($)	Apr. 26, 2024 USD ($)	Dec. 31, 2023 USD ($)	Oct. 07, 2023 USD ($)	May 25, 2023 USD ($)	May 22, 2023 USD ($)	May 22, 2023 BRL (R$)	Mar. 10, 2022 USD ($)	Aug. 20, 2021 USD ($)	Aug. 20, 2021 BRL (R$)	Jul. 10, 2020 USD ($)	Feb. 26, 2020	Apr. 19, 2019 USD ($)	Apr. 08, 2019 USD ($)	Nov. 28, 2018 USD ($)	Aug. 06, 2018 USD ($)	Mar. 19, 2018 USD ($)	Aug. 23, 2017 BRL (R$)	Aug. 22, 2017 BRL (R$)
Debt Instrument [Line Items]
Line of credit, maturity date extension																										2 years
Deferred financing cost									$ 9,300,000			$ 9,300,000					$ 6,500,000
Redemption price as percentage of principal amount					101.00%
Carrying amount of debt component									1,440,689,000			1,440,689,000					1,183,506,000
Long-term debt									1,440,689,000			1,440,689,000					944,326,000
Revolving credit facility \| BGC Credit Agreement \| Related Party
Debt Instrument [Line Items]
Line of credit facility, outstanding amount	$ 275,000,000.0								0	$ 275,000,000.0		0					0
Interest expense recorded									0		$ 0	1,100,000	$ 0
Principal amount of debt component			$ 400,000,000												$ 400,000,000															$ 400,000,000	$ 250,000,000.0
Debt instrument, basis point			(0.25%)
Average interest rate			1.00%							6.92%
Repayment of outstanding borrowings	$ 275,000,000.0
Proceeds from borrowings		$ 275,000,000
Unsecured Credit Agreement \| Senior revolving credit agreement
Debt Instrument [Line Items]
Maximum revolving credit																$ 475,000,000						$ 375,000,000							$ 350,000,000.0
Interest expense recorded									$ 4,200,000		$ 1,600,000	$ 7,900,000	$ 2,800,000
Average interest rate									7.17%		6.79%	7.18%	6.64%
Repayment of outstanding borrowings		$ 240,000,000
Unsecured Credit Agreement \| New Senior Revolving Credit Agreement
Debt Instrument [Line Items]
Line of credit facility, outstanding amount									$ 0			$ 0					239,200,000
Deferred financing cost																	800,000
Five Point Three Seven Five Percent Senior Notes [Member]
Debt Instrument [Line Items]
Interest expense recorded											$ 6,400,000		$ 12,800,000
Stated interest rate						5.375%
Principal amount of debt component						$ 450,000,000.0
Redemption price as percentage of principal amount						101.00%
Carrying amount of debt component						$ 444,200,000
Debt issuance costs						$ 5,800,000
Five Point Three Seven Five Percent Senior Notes [Member] \| Level 2
Debt Instrument [Line Items]
Stated interest rate									5.375%			5.375%
BGC Group $4.375% Senior Notes due December 15, 2025
Debt Instrument [Line Items]
Interest expense recorded											0		0
Stated interest rate					3.75%
Principal amount of debt component					$ 300,000,000.0
Carrying amount of debt component					296,100,000				$ 255,300,000			$ 255,300,000
Debt issuance costs					$ 3,900,000
BGC Group $4.375% Senior Notes due December 15, 2025 \| Level 2
Debt Instrument [Line Items]
Stated interest rate									3.75%			3.75%
BGC Partners $4.375% Senior Notes due December 15, 2025
Debt Instrument [Line Items]
Interest expense recorded									$ 100,000		3,400,000	$ 300,000	6,900,000
Stated interest rate																									4.375%
Principal amount of debt component																									$ 300,000,000.0
Carrying amount of debt component																									296,800,000
Debt issuance costs																									$ 3,200,000
BGC Partners $4.375% Senior Notes due December 15, 2025 \| Level 2
Debt Instrument [Line Items]
Stated interest rate									4.375%			4.375%
3.77% secured loan arrangement \| Secured loan arrangements
Debt Instrument [Line Items]
Interest expense recorded											0		0
Stated interest rate																												3.77%
Debt instrument gross amount																												$ 15,000,000.0
Outstanding balance of the secured loan arrangements									$ 0			$ 0					0
3.89% secured loan arrangement \| Secured loan arrangements
Debt Instrument [Line Items]
Interest expense recorded											0		0
Stated interest rate																											3.89%
Debt instrument gross amount																											$ 10,000,000.0
Outstanding balance of the secured loan arrangements									0			0					0
Unsecured loan agreement \| Short term loans \| Itau Unibanco S.A.
Debt Instrument [Line Items]
Maximum revolving credit								$ 4,000,000.0	0			0					0
Interest expense recorded											100,000		200,000
Debt instrument, basis point								3.20%
Unsecured loan agreement \| Short term loans \| Banco Daycoval S.A.
Debt Instrument [Line Items]
Maximum revolving credit \| R$																																	R$ 20.0
Unsecured credit agreement \| Intra-day overdraft credit line
Debt Instrument [Line Items]
Line of credit facility, fee									0		0	100,000	100,000
Unsecured credit agreement \| Intra-day overdraft credit line \| Itau Unibanco S.A.
Debt Instrument [Line Items]
Maximum revolving credit							$ 9,000,000.0													$ 12,600,000	R$ 70.0		$ 10,800,000	R$ 60.0								R$ 50.0
Line of credit facility, outstanding amount									0			$ 0					0
Line of credit facility, fee percentage							1.32%
BGC Group $8.000% Senior Notes due May 25, 2028
Debt Instrument [Line Items]
Interest expense recorded									$ 100,000		2,800,000		2,800,000
Stated interest rate									8.00%			8.00%							8.00%
Principal amount of debt component																			$ 350,000,000
Carrying amount of debt component																			346,600,000
Debt issuance costs																			$ 3,400,000
BGC Partners $8.000% Senior Notes due May 25, 2028
Debt Instrument [Line Items]
Stated interest rate									8.00%			8.00%							8.00%
Long-term debt									$ 2,751,000			$ 2,751,000					2,748,000
BGC Partners $8.000% Senior Notes due May 25, 2028 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt																		$ 2,800,000
BGC Group $3.750% Senior Notes due October 1, 2024
Debt Instrument [Line Items]
Interest expense recorded									$ 2,600,000			$ 5,300,000
Stated interest rate				3.75%					3.75%			3.75%
Long-term debt									$ 255,306,000			$ 255,306,000					254,814,000
BGC Group $3.750% Senior Notes due October 1, 2024 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt				$ 255,500,000
BGC Partners $3.750% Senior Notes due October 1, 2024
Debt Instrument [Line Items]
Interest expense recorded									$ 400,000		3,000,000	$ 900,000	6,000,000
Stated interest rate					3.75%				3.75%			3.75%
Long-term debt									$ 44,444,000			$ 44,444,000					44,383,000
BGC Partners $3.750% Senior Notes due October 1, 2024 \| Parent Company
Debt Instrument [Line Items]
Stated interest rate					3.75%
Long-term debt																		44,500,000
BGC Partners $3.750% Senior Notes due October 1, 2024 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt				$ 255,500,000
BGC Group $4.375% Senior Notes due December 15, 2025
Debt Instrument [Line Items]
Interest expense recorded									$ 3,300,000		0	$ 6,700,000	0
Stated interest rate				4.375%					4.375%			4.375%
Redemption price as percentage of principal amount				101.00%
Long-term debt									$ 287,096,000			$ 287,096,000					286,729,000
BGC Group $4.375% Senior Notes due December 15, 2025 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt				$ 288,200,000					$ 14,500,000			$ 14,500,000
BGC Partners $4.375% Senior Notes due December 15, 2025
Debt Instrument [Line Items]
Stated interest rate					4.375%				4.375%			4.375%													4.375%
Long-term debt									$ 11,812,000			$ 11,812,000					11,800,000
BGC Partners $4.375% Senior Notes due December 15, 2025 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt																		$ 11,800,000
BGC Group $8.000% Senior Notes due May 25, 2028
Debt Instrument [Line Items]
Interest expense recorded									$ 7,100,000		$ 0	$ 14,300,000	$ 0
Stated interest rate				8.00%					8.00%			8.00%
Redemption price as percentage of principal amount				101.00%
Long-term debt									$ 344,236,000			$ 344,236,000					343,852,000
BGC Group $8.000% Senior Notes due May 25, 2028 \| Senior Notes
Debt Instrument [Line Items]
Long-term debt				$ 347,200,000
BGC Group Notes Exchange Offer
Debt Instrument [Line Items]
Debt issuance costs				$ 900,000
BGC Group 6.600% Senior Notes due June 10, 2029
Debt Instrument [Line Items]
Interest expense recorded									1,900,000			1,900,000
Stated interest rate														6.60%
Principal amount of debt component														$ 500,000,000
Carrying amount of debt component														495,000,000.0
Debt issuance costs														$ 5,000,000.0
Long-term debt									$ 495,044,000			$ 495,044,000					$ 0