Name:	bgcp_DisposalGroupIncludingDiscontinuedOperationTransactionAndOtherCosts
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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

The cash inflow associated with working capital adjustments related to the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

No definition available.

Name:	bgcp_DisposalGroupIncludingDiscontinuedOperationWorkingCapitalAdjustment
Namespace Prefix:	bgcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of accounts payable and accrued liabilities attributable to disposal group.

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationAccountsPayableAndAccruedLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of deferred revenue attributable to disposal group.

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationDeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

For the disposal group, including a component of the entity (discontinued operation), carrying amount as of the balance sheet date of assets not otherwise specified.

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationOtherAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

For the disposal group, including a component of the entity (discontinued operation), carrying value (net of accumulated depreciation and any write-downs) of tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

The gain (loss) resulting from the sale of a disposal group that is not a discontinued operation. It is included in income from continuing operations before income taxes in the income statement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 205

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228

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

The cash inflow associated with the amount received from the sale of a portion of the company's business, for example a segment, division, branch or other business, during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 12

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3179-108585