XML 138 R122.htm IDEA: XBRL DOCUMENT
v3.20.4

Compensation - Summary of Compensation Expense Related to Amortization of LPUs Held by BGC Employees (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
LPU amortization | $ 74,282 | $ 41,721 | $ 6,346
Stated vesting schedule [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
LPU amortization | 73,034 | 42,060 | 2,462
Post-termination payout [Member] |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |
LPU amortization | $ 1,248 | $ (339) | $ 3,884

X
- Definition Share based compensation arrangement by share based payment award limited partners capital units amortization. + References No definition available. + Details
Name: | bgcp_ShareBasedCompensationArrangementByShareBasedPaymentAwardLimitedPartnersCapitalUnitsAmortization
Namespace Prefix: | bgcp_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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
- Details
Name: | us-gaap_PlanNameAxis=bgcp_StatedVestingScheduleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=bgcp_PostTerminationPayoutMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |