Debt Instrument, Issued During Period, Principal Amount, Net Of Retirements

No definition available.

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

- Definition

Long-term Debt, Matures In 2024

+ References

No definition available.

+ Details

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

- Definition

Number of Warehouse Credit Commitments

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Principal Outstanding

+ References

No definition available.

+ Details

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

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
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+ Details

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

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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+ Details

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Data Type:	num:percentItemType
Balance Type:	na
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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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-Publisher FASB
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+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

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

- Definition

The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

+ References

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+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

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Balance Type:	credit
Period Type:	duration

- Details

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- Details

Name:	dei_LegalEntityAxis=jef_JefferiesGroupLLCMember
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- Details

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- Details

Name:	us-gaap_DebtInstrumentAxis=jef_EightPointFivePercentageSeniorNotesDueTwoThousandNineteenMember
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- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_RevolvingCreditFacilityMember
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- Details

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- Details

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- Details

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Long-Term Debt (Narrative) (Details)		9 Months Ended
Long-Term Debt (Narrative) (Details)	Jul. 19, 2019 USD ($)	Aug. 31, 2019 USD ($) Contract	Nov. 30, 2018 USD ($)
Debt Instrument [Line Items]
Long-term debt		$ 7,968,785,000	$ 7,617,563,000
Structured notes \| Jefferies Group
Debt Instrument [Line Items]
Principal amount of debt issued, net of retirements		$ 283,200,000
1.00% Euro Medium Term Notes, due July 19, 2024 \| Jefferies Group
Debt Instrument [Line Items]
Debt face amount	$ 2,500,000,000
Interest rate		1.00%
Principal amount	553,600,000
Proceeds from issuance of debt	$ 551,400,000
8.50% Senior Notes, due July 15, 2019
Debt Instrument [Line Items]
Interest rate		8.50%
8.50% Senior Notes, due July 15, 2019 \| Jefferies Group
Debt Instrument [Line Items]
Repayments of debt		$ 680,800,000
Revolving Credit Facility \| Jefferies Group
Debt Instrument [Line Items]
Debt face amount		190,000,000.0
HomeFed EB-5 Program debt
Debt Instrument [Line Items]
Long-term debt		131,395,000	0
Long-term debt, matured in 2024		$ 124,500,000
Secured Debt \| Foursight Capital Credit Facilities
Debt Instrument [Line Items]
Number of warehouse credit commitment \| Contract		2
Credit facility maximum amount		$ 175,000,000.0
Long-term debt		$ 0	$ 0