Increase (Decrease) of Long-term Debt

No definition available.

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

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
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-Section 55
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-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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

- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Namespace Prefix:	us-gaap_
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

Percentage of principal amount of debt redeemed.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentRedemptionPricePercentageOfPrincipalAmountRedeemed
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
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-Publisher FASB
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-Section S99
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-Publisher FASB
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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

- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585

+ Details

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Namespace Prefix:	us-gaap_
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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jef_StructuredNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jef_A2.5BillionEuroMediumTermNoteMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=jef_A1.000EuroMediumTermNotesDue2024Member
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=jef_EightPointFivePercentageSeniorNotesDueTwoThousandNineteenMember
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- 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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Period Type:

Long-Term Debt - Additional Information (Details) - USD ($)		9 Months Ended
	Jan. 05, 2018	Aug. 31, 2019	Jul. 19, 2019	Nov. 30, 2018	Aug. 31, 2018	May 16, 2018	Apr. 30, 2018	Nov. 30, 2017
Debt Instrument [Line Items]
Long-term debt at fair value		$ 1,014,509,000		$ 686,170,000
Increase of long-term debt		220,900,000
Long-term debt		6,767,163,000		6,546,283,000
Redemption price as percentage of principal amount redeemed	100.00%
Unsecured Debt
Debt Instrument [Line Items]
Long-term debt		6,578,236,000		6,362,744,000
Structured Notes
Debt Instrument [Line Items]
Debt principal amount		283,200,000
Structured Notes \| Unsecured Debt
Debt Instrument [Line Items]
Debt principal amount					$ 162,600,000
Long-term debt		1,014,509,000		686,170,000
$2.5 Billion Euro Medium Term Note \| Unsecured Debt
Debt Instrument [Line Items]
Debt principal amount			$ 2,500,000,000
1.000% Euro Medium Term Notes \| Unsecured Debt
Debt Instrument [Line Items]
Debt principal amount			$ 553,600,000
Proceeds from debt		$ 551,400,000
Debt instrument interest rate		1.00%	1.00%
Long-term debt		$ 546,855,000		0
8.500% Senior Notes \| Unsecured Debt
Debt Instrument [Line Items]
Repayments of debt		$ 680,800,000
Debt instrument interest rate		8.50%
Long-term debt		$ 0		699,659,000
4.150% Senior Notes \| Unsecured Debt
Debt Instrument [Line Items]
Debt principal amount					$ 1,000,000,000.0
Debt instrument interest rate		4.15%
Long-term debt		$ 988,440,000		987,788,000
3.875% Convertible Senior Debentures \| Unsecured Debt
Debt Instrument [Line Items]
Long-term debt								$ 324,800,000
5.125% Senior Notes \| Unsecured Debt
Debt Instrument [Line Items]
Debt instrument interest rate							5.125%
Long-term debt							$ 668,300,000
Revolving Credit Facility \| Secured Debt
Debt Instrument [Line Items]
Debt principal amount						$ 190,000,000.0
Long-term debt		188,927,000		183,539,000
Level 2 and Level 3
Debt Instrument [Line Items]
Long-term debt at fair value		$ 7,046,600,000		$ 6,423,600,000