Expected Period For Liquidation Of Underlying Assets Maximum

No definition available.

Name:	jef_ExpectedPeriodForLiquidationOfUnderlyingAssetsMaximum
Namespace Prefix:	jef_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected Period For Liquidation Of Underlying Assets Minimum

+ References

No definition available.

+ Details

Name:	jef_ExpectedPeriodForLiquidationOfUnderlyingAssetsMinimum
Namespace Prefix:	jef_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Investments at fair value that cannot be redeemed at reporting date and are subject to a prior written redemption request.

+ References

No definition available.

+ Details

Name:	jef_NoticePeriodRedemptionOfInvestmentsPriorWrittenNoticePeriod
Namespace Prefix:	jef_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Investments redeemable within 60-90 days

+ References

No definition available.

+ Details

Name:	jef_RedeemableInvestments
Namespace Prefix:	jef_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value of investment other than investment in equity security, investment in debt security and equity method investment. Includes, but is not limited to, investment in certain entities that calculate net asset value per share. Example includes, but is not limited to, investment in hedge fund, venture capital fund, private equity fund, and real estate partnership or fund.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=SL6742756-110258

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 35
-Paragraph 54B
-URI http://asc.fasb.org/extlink&oid=99392525&loc=SL7495116-110257

+ Details

Name:	us-gaap_AlternativeInvestment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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

Name:	us-gaap_FairValueInvestmentsEntitiesThatCalculateNetAssetValuePerShareLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=SL6742756-110258

+ Details

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

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_HedgeFundsEquityLongShortMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_PrivateEquityFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=jef_CommodityFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=jef_MultiassetFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=jef_OtherFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Fair Value Disclosures - Investments Measured at Fair Value Based on Net Asset Value Per Share (Details) - USD ($) $ in Thousands	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	Nov. 30, 2018
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 890,137	$ 570,310
Unfunded Commitments	11,823	12,108
Equity Long/Short Hedge Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	303,941	291,593
Unfunded Commitments	$ 0	$ 0
Percentage of redeemable investments	6.00%	6.00%
Notice period redemption of investment prior written notice period	60 days	60 days
Equity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 28,777	$ 27,952
Unfunded Commitments	$ 11,823	12,108
Expected period for the liquidation of the underlying assets, minimum			1 year
Expected period for the liquidation of the underlying assets, maximum	9 years
Commodity Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 14,650	16,025
Unfunded Commitments	$ 0	0
Notice period redemption of investment prior written notice period	60 days			60 days
Multi-asset Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 542,609	234,583
Unfunded Commitments	$ 0	$ 0
Percentage of redeemable investments	2.00%	5.00%
Notice period redemption of investment prior written notice period	30 days			30 days
Other Funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 160	$ 157
Unfunded Commitments	$ 0	$ 0