Name:	jef_CmbsSecuritizationAssets
Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Collateralized Loan Obligations Securitization Assets

No definition available.

Name:	jef_CollateralizedLoanObligationsSecuritizationAssets
Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Other Securitization Assets

No definition available.

Name:	jef_OtherSecuritizationAssets
Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Represents unpaid principal amount of assets in residential mortgage backed securitization vehicles at the balance sheet date.

No definition available.

Name:	jef_RmbsSecuritizationAssets
Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Fair value portion of interest continued to be held by a transferor after transferring financial assets to a third party.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 10
-Section 15
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=68074228&loc=d3e94415-111705

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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.

No definition available.

Name:	us-gaap_ScheduleOfTradingSecuritiesAndOtherTradingAssetsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Period Type:	duration

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Namespace Prefix:
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Period Type:

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=jef_UsGovernmentAgencyIssuedCmbsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CollateralizedLoanObligationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: