Amount of total errors being corrected in the correcting adjustment.

Name:	jef_AdjustmentsRelatedToNetEarningsToCommonStockHolders
Namespace Prefix:	jef
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustment to correct differences with the former clearing bank during the prior period.

+ Details

Name:	jef_DifferencesWithClearingBank
Namespace Prefix:	jef
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Adjustment to correct the netting of interest income and interest expense during the prior period.

+ Details

Name:	jef_NettingOfInterestRevenuesAndExpense
Namespace Prefix:	jef
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Adjustment to correct immaterial differences during the prior period.

+ Details

Name:	jef_OtherItems
Namespace Prefix:	jef
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 9
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6920599&loc=d3e1377-109256

+ Details

Name:	us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_PriorPeriodAdjustmentAbstract
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Organization and Basis of Presentation (Details) (USD $) In Thousands	3 Months Ended		8 Months Ended	9 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2010	Aug. 31, 2011
Decrease in Net earnings to common shareholders
Previously reported Net earnings to common shareholders	$ 68,275	$ 44,754	$ 160,952	$ 236,232
Total adjustments		(1,502)	(3,843)
Scenario, Previously Reported [Member]
Decrease in Net earnings to common shareholders
Previously reported Net earnings to common shareholders		46,256	164,795
Restatement Adjustment [Member]
Decrease in Net earnings to common shareholders
Netting of interest revenues and expense		0	0
Differences with clearing bank		(1,738)	(3,453)
Other items		$ 236	$ (390)