XML 132 R119.htm IDEA: XBRL DOCUMENT v3.8.0.1

Regulatory Requirements - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Minimum period required for financial resources to cover operating costs	1 year
Minimum period required for cash or highly liquid securities to cover operating costs	6 months
Net assets held by regulated subsidiaries	$ 582,900
Amount of capital in excess of aggregate regulatory requirements	$ 307,600
Percentage of Freddie Mac's liquidity requirement of outstanding principal of TAH loans serviced	8.00%
Other Assets [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Outstanding borrower advances	$ 63	$ 120
Seller/Servicer Agreements [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Amount of capital in excess of aggregate regulatory requirements	$ 426,000

X

- Definition

Outstanding borrower advances to investors.

+ References

No definition available.

+ Details

Name:	bgcp_OutstandingBorrowerAdvancesToInvestors
Namespace Prefix:	bgcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Percentage of liquidity requirement of outstanding principal of targeted affordable housing loans serviced.

+ References

No definition available.

+ Details

Name:	bgcp_PercentageOfLiquidityRequirementOfOutstandingPrincipalOfTargetedAffordableHousingLoansServiced
Namespace Prefix:	bgcp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Regulatory requirement minimum period of cash or highly liquid securities to cover operating costs.

+ References

No definition available.

+ Details

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

X

- Definition

Regulatory requirement minimum period of financial resources to cover operating costs.

+ References

No definition available.

+ Details

Name:	bgcp_RegulatoryRequirementMinimumPeriodOfFinancialResourcesToCoverOperatingCosts
Namespace Prefix:	bgcp_
Data Type:	xbrli:durationItemType
Balance Type:	na
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_ComplianceWithRegulatoryCapitalRequirementsUnderBankingRegulationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The amount by which the company's Total Capital exceeds the minimum required for capital adequacy purposes.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=84167132&loc=SL5958568-112826

+ Details

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

X

- Definition

The net amount of all regulatory assets less all regulatory liabilities as of the end of the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

+ Details

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

X

- Details

Name:	us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_TypeOfArrangementAxis=bgcp_SellerServicerAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: