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Compensation - Summary of Outstanding LPUs Held by BGC Employees with Stated Vesting (Detail) - LPUs [Member] - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
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Mar. 31, 2021 | Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Aggregate estimated grant date fair value | $ 177,489 | $ 201,239
BGC Holdings LPUs [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Aggregate estimated grant date fair value | 42,607 | 44,529
Newmark Holdings LPUs [Member] |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Aggregate estimated grant date fair value | $ 326 | $ 353

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- Definition Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash. + 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 (d)(2) -URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901 + 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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- Details
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