Commitments, Contingencies and Guarantees - Guarantees (Detail) $ in Millions	Feb. 29, 2016 USD ($)
Guarantee Obligations [Line Items]
Notional/ Maximum Payout	$ 3,600.4
Derivative contracts - non-credit related [Member]
Guarantee Obligations [Line Items]
2016	13,418.6
2017	1,048.6
2018 and 2019	348.1
2020 and 2021	0.0
2022 and Later	426.7
Notional/ Maximum Payout	15,242.0
Written derivative contracts - credit related [Member]
Guarantee Obligations [Line Items]
2016	0.0
2017	0.0
2018 and 2019	90.2
2020 and 2021	197.0
2022 and Later	2.5
Notional/ Maximum Payout	289.7
Derivatives [Member]
Guarantee Obligations [Line Items]
2016	13,418.6
2017	1,048.6
2018 and 2019	438.3
2020 and 2021	197.0
2022 and Later	429.2
Notional/ Maximum Payout	$ 15,531.7

Guarantees with a remaining term that matures during the fiscal year. These may include derivative guarantees, etc.

No definition available.

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Data Type:	xbrli:monetaryItemType
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- Definition

Guarantees expected to be due within 5 to 6 fiscal years. These may include, derivative guarantees, etc.

+ References

No definition available.

+ Details

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Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Guarantees expected to be due within 3 to 4 fiscal years. These may include, derivative guarantees, etc.

+ References

No definition available.

+ Details

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Namespace Prefix:	jef_
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Balance Type:	credit
Period Type:	instant

- Definition

Guarantees expected to be due within 2 fiscal years. These may include, derivative guarantees, etc.

+ References

No definition available.

+ Details

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

- Definition

Guarantees expected to be due within 7 fiscal years and thereafter. These may include, derivative guarantees, etc

+ References

No definition available.

+ Details

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Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

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Namespace Prefix:	us-gaap_
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Period Type:	duration

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

+ Details

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- Details

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- Details

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Balance Type:
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- Details

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