Area of sublease.

No definition available.

Name:	bgcp_AreaOfSublease
Namespace Prefix:	bgcp_
Data Type:	dtr-types:areaItemType
Balance Type:	na
Period Type:	duration

- Definition

Lessee, Operating Lease, Monthly Rent Expense

+ References

No definition available.

+ Details

Name:	bgcp_LesseeOperatingLeaseMonthlyRentExpense
Namespace Prefix:	bgcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Lessee operating lease sublease term.

+ References

No definition available.

+ Details

Name:	bgcp_LesseeOperatingLeaseSubleaseTerm
Namespace Prefix:	bgcp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 55
-Paragraph 53
-URI https://asc.fasb.org/extlink&oid=123414884&loc=SL77918982-209971

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=128292326&loc=SL77918686-209980

+ Details

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

- Definition

Cash payments to lessor's for use of assets under operating leases.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3536-108585

+ Details

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

- 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.

+ References

No definition available.

+ Details

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

- Details

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

- Details

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

- Details

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

Related Party Transactions - BGC Sublease from Newmark (Details) $ in Thousands	1 Months Ended	12 Months Ended
	May 31, 2020 USD ($) ft²	Dec. 31, 2021 USD ($)	May 31, 2021 USD ($)
RKF Retail Holdings LLC
Related Party Transaction [Line Items]
Lessee operating lease sublease term	1 year
Area of sublease \| ft²	21,000
BGC U.S OpCo
Related Party Transaction [Line Items]
Operating lease cost	$ 1,100
Rent payment under lease term		$ 500
Poten & Partners
Related Party Transaction [Line Items]
Monthly rent expense			$ 15