Long-Term Debt - Additional Information (Details) - USD ($)	12 Months Ended
Nov. 30, 2021	Nov. 30, 2020
Debt Instrument [Line Items]
Increase of long-term debt	$ 1,140,000,000	$ 107,700,000
Long-term debt	8,039,826,000	6,895,680,000
Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	7,315,844,000	6,655,948,000
Secured long-term debt
Debt Instrument [Line Items]
Long-term debt	100,000,000	50,000,000
Secured long-term debt \| Secured Credit Facility
Debt Instrument [Line Items]
Long-term debt	375,000,000	0
Secured long-term debt \| Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	$ 248,982,000	189,732,000
2.625% Senior Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument interest rate	2.625%
Debt principal amount	$ 1,000,000,000
2.625% Senior Notes \| Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	$ 988,059,000	0
Debt instrument interest rate	2.625%
Floating Rate Senior Notes \| Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	$ 61,703,000	$ 0
Debt principal amount	$ 62,300,000
5.125% Senior Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument interest rate	5.125%	5.125%
Debt principal amount	$ 750,000,000	$ 150,000,000
5.125% Senior Notes \| Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	$ 0	759,901,000
Debt instrument interest rate	5.125%
Unsecured Revolving Credit Facility \| Unsecured long-term debt
Debt Instrument [Line Items]
Increase of long-term debt	$ 349,000,000
Long-term debt	348,951,000	0
Secured Credit Facility \| Secured long-term debt
Debt Instrument [Line Items]
Increase of long-term debt	484,300,000
Structured notes
Debt Instrument [Line Items]
Debt principal amount	175,600,000	325,500,000
Structured notes \| Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	1,843,598,000	$ 1,712,245,000
2.375% Euro Medium Term Notes \| Medium-term notes
Debt Instrument [Line Items]
Debt instrument interest rate		2.375%
6.875% Senior Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument interest rate		6.875%
2.750% Senior Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument interest rate		2.75%
Debt principal amount		$ 500,000,000
2.750% Senior Notes \| Unsecured long-term debt
Debt Instrument [Line Items]
Long-term debt	$ 460,724,000	$ 485,134,000
Debt instrument interest rate	2.75%
Secured bank loan \| Secured long-term debt
Debt Instrument [Line Items]
Revolving credit facility maximum principal amount	$ 100,000,000
Secured bank loan \| Secured long-term debt \| LIBOR
Debt Instrument [Line Items]
Debt basis spread on variable rate	1.25%

Increase (Decrease) of Long-term Debt

No definition available.

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

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
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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+ Details

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Period Type:	instant

- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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- 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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- 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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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+ Details

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
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