Variable Interest Entities - Non-Consolidated Variable Interest Entities (Detail) (Variable Interest Entity Not Primary Beneficiary [Member], USD $) In Millions, unless otherwise specified	Feb. 28, 2014	Nov. 30, 2013
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	$ 2,664.8	$ 2,122.3
Carrying Amount, Liabilities	2.3	0.2
Maximum exposure to loss in non-consolidated VIEs	2,947.9	2,227.2
Size of the variable interest entity measured by total assets	95,644.9	85,594.0
Collateralized loan obligations securitizations [Member]
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	24.2	11.9
Carrying Amount, Liabilities	2.3	0.2
Maximum exposure to loss in non-consolidated VIEs	281.1	88.8
Size of the variable interest entity measured by total assets	2,076.8	1,122.3
Agency mortgage- and asset-backed securitizations [Member]
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	1,733.2	1,226.0
Carrying Amount, Liabilities
Maximum exposure to loss in non-consolidated VIEs	1,733.2	1,226.0
Size of the variable interest entity measured by total assets	3,463.3	5,857.3
Non-agency mortgage- and asset-backed securitizations [Member]
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	862.4	840.1
Carrying Amount, Liabilities
Maximum exposure to loss in non-consolidated VIEs	862.4	840.1
Size of the variable interest entity measured by total assets	89,546.7	78,070.8
Asset management vehicle [Member]
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	3.7	3.5
Carrying Amount, Liabilities
Maximum exposure to loss in non-consolidated VIEs	3.7	3.5
Size of the variable interest entity measured by total assets	470.0	454.2
Private equity vehicles [Member]
Assets and Liabilities of Consolidated VIEs [Line Items]
Carrying Amount, Assets	41.3	40.8
Carrying Amount, Liabilities
Maximum exposure to loss in non-consolidated VIEs	67.5	68.8
Size of the variable interest entity measured by total assets	$ 88.1	$ 89.4

Variable Interest Entity Carrying Amount Of Assets Non Consolidated Vie

No definition available.

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

- Definition

The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph b

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5728-111685

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7880789&loc=d3e5747-111685

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4/FIN46(R)

-Paragraph C6

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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

- Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Carrying amount of the assets in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

+ Details

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

- Definition

Carrying amount of the liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), where the reporting entity is not the VIE's primary beneficiary.

+ References

+ Details

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