XML 106 R92.htm IDEA: XBRL DOCUMENT
v3.21.2

Compensation - Summary of the BGC Holdings and Newmark Holdings LPUs held by BGC Employees (Detail) - LPUs - shares | Jun. 30, 2021 | Dec. 31, 2020
--- | --- | ---
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 118,690,000 | 137,652,000
Newmark |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 11,519,000 | 13,202,000
Regular Units |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 82,508,000 |
Regular Units | Newmark |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 8,659,000 |
Preferred Units |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 36,182,000 |
Preferred Units | Newmark |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Balance outstanding (in shares) | 2,860,000 |

X
- 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_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(ii) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=bgcp_LimitedPartnershipUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=bgcp_NewmarkMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PreferredUnitsByNameAxis=bgcp_RegularUnitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PreferredUnitsByNameAxis=bgcp_PreferredUnitsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |