Other shares issuable

No definition available.

Name:	jef_OtherSharesIssuable
Namespace Prefix:	jef_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Potential Maximum Increase to Common Shares Outstanding from Restricted Stock and Other Shares

+ References

No definition available.

+ Details

Name:	jef_PotentialMaximumIncreaseToCommonSharesOutstandingFromRestrictedStockAndOtherShares
Namespace Prefix:	jef_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Restricted Cash Awards, Compensation Cost Not Yet Recognized

+ References

No definition available.

+ Details

Name:	jef_RestrictedCashAwardsCompensationCostNotYetRecognized
Namespace Prefix:	jef_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Restricted Cash Awards, Compensation Cost Not Yet Recognized, Period For Recognition

+ References

No definition available.

+ Details

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

- Definition

Share-based Compensation Arrangement by Share-based Payment Award, Amortization Period

+ References

No definition available.

+ Details

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

- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of tax benefit for recognition of expense of award under share-based payment arrangement.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of noncash expense for share-based payment arrangement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

+ Details

Name:	us-gaap_ShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

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

- Definition

Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_AwardTypeAxis=jef_SignonandRetentionAwardsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=jef_RestrictedStockWithFutureServiceRequiredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=jef_RestrictedStockUnitsWithFutureServiceRequiredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=jef_RestrictedStockUnitsWithNoFutureServiceRequiredMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Compensation Plans (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation	$ 10,700	$ 13,100	$ 20,684	$ 24,886
Tax benefit for issuance of share-based awards	2,700	$ 3,400	5,300	$ 6,300
Total unrecognized compensation costs related to nonvested share-based compensation plans	$ 61,900		$ 61,900
Total unrecognized compensation costs related to nonvested share-based compensation plans, period for recognition			2 years 1 month 6 days
Other shares issuable (in shares)	1,092		1,092
Potential maximum increase to common shares outstanding from restricted stock and other shares (in shares)	23,563		23,563
Restricted cash awards, cost expected to be recognized	$ 627,400		$ 627,400
Restricted cash awards, cost expected to be recognized, period			3 years
Sign-on and retention awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period for award granted			4 years
Award amortization period			4 years
Restricted stock with future service required
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments, outstanding (in shares)	1,838		1,838
Restricted stock units with future service required
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments, outstanding (in shares)	4,149		4,149
Restricted stock units with no future service required
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option equity instruments, outstanding (in shares)	18,322		18,322