Leases - Additional Information (Detail)	12 Months Ended
Dec. 31, 2021
Minimum
Operating Leased Assets [Line Items]
Remaining lease term, operating lease	2 months 12 days
Lease renewal term, operating lease	1 year
Maximum
Operating Leased Assets [Line Items]
Remaining lease term, operating lease	17 years 7 months 6 days
Lease renewal term, operating lease	10 years
Lease renewal increments term, operating lease (up to)	10 years

Lessee operating lease renewal increments term.

No definition available.

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

- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918673-209980

+ Details

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Balance Type:	na
Period Type:	instant

- Definition

Term of lessee's operating lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

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- 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

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- Details

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- Details

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