Other Fair Value Information [Abstract] Other Fair Value Information [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Measurement Basis [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Amount Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Notes and loans receivable Notes and Loans Receivable Notes and loans receivable Short-term borrowings Short-term Debt Long-term debt Long-term Debt Income Tax Disclosure [Abstract] Income Taxes [Table] Income Taxes [Table] Income Taxes [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Jefferies Group Jefferies Group LLC [Member] Jefferies Group LLC Income Taxes [Line Items] Income Taxes [Line Items] Unrecognized tax benefits Unrecognized Tax Benefits Interest included in unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Accrued Income taxes benefit Income Tax Expense (Benefit) Decrease of deferred tax liabilities Increase (Decrease) Of Deferred Tax Liabilities Increase (Decrease) Of Deferred Tax Liabilities Recognition of accumulated other comprehensive income lodged taxes Recognition Of Accumulated Other Comprehensive Income Lodged Taxes Recognition Of Accumulated Other Comprehensive Income Lodged Taxes Lodged tax effect Lodged Tax Effect Lodged Tax Effect Decrease of income tax provision Income Tax Expense (Benefit) From Reversal of Valuation Allowance Income Tax Expense (Benefit) From Reversal of Valuation Allowance Fair Value Disclosures [Abstract] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Investment, Name [Axis] Investment, Name [Axis] Investment, Name [Domain] Investment, Name [Domain] The We Company The We Company [Member] The We Company [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fair Value Measured at NAV Fair Value Measured at Net Asset Value Per Share [Member] Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] Equity Long/Short Hedge Funds Hedge Funds, Equity Long (Short) [Member] Equity Funds Equity Funds [Member] Commodity Funds Commodity Funds [Member] Commodity Funds [Member] Multi-asset Funds Multi-asset Funds [Member] Multi-asset Funds [Member] Other Funds Other Funds [Member] Other Funds [Member] Investments Redeemable Prior Written Notice Period [Axis] Investments Redeemable Prior Written Notice Period [Axis] Investments Redeemable Prior Written Notice Period [Axis] Investments Redeemable Prior Written Notice Period [Domain] Investments Redeemable Prior Written Notice Period [Domain] Investments Redeemable Prior Written Notice Period [Axis] 60 days prior written notice Sixty Days Prior Written Notice [Member] Sixty Days Prior Written Notice [Member] 30 days prior written notice 30 Days Prior Written Notice [Member] 30 Days Prior Written Notice [Member] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Fair Value Alternative Investment Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Percentage of investment at fair value, redemption restriction Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Restriction, Percentage Investment redemption restriction period Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Redemption Restriction, Period in Effect Percentage of investments redeemable Percentage Of Investments Redeemable Percentage Of Investments Redeemable Notice period redemption of investments prior written notice period Notice Period Redemption Of Investments Prior Written Notice Period Investments at fair value that cannot be redeemed at reporting date and are subject to a prior written redemption request. Percentage of investments redeemed during period Percentage Of Investments Redeemed During Period Percentage Of Investments Redeemed During Period Estimated period for the liquidation of the underlying assets Estimated period for the liquidation of the underlying assets Estimated period for the liquidation of the underlying assets, Payments to acquire investments Payments to Acquire Investments Ownership percentage Ownership Percentage Ownership Percentage Trading assets, at fair value Financial instruments owned trading assets, at fair value Financial Instruments, Owned, Trading Assets, at Fair Value Discontinued Operations and Disposal Groups [Abstract] Summary of results of discontinued operations Disposal Groups, Including Discontinued Operations [Table Text Block] Aggregate Indebtedness [Abstract] Long-Term Debt Debt Disclosure [Text Block] Equity Method Investments and Joint Ventures [Abstract] Schedule of Equity Method Investments [Table] Schedule of Equity Method Investments [Table] Disposal Group Name [Axis] Disposal Group Name [Axis] Disposal Group Name [Domain] Disposal Group Name [Domain] National Beef National Beef [Member] National Beef [Member] Disposal Group Classification [Axis] Disposal Group Classification [Axis] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Discontinued operations, disposed of by sale Discontinued Operations, Disposed of by Sale [Member] Schedule of Equity Method Investments [Line Items] Schedule of Equity Method Investments [Line Items] Equity method investment, ownership percentage Equity Method Investment, Ownership Percentage Weighted average useful life Weighted Average Life Of Assets and Liabilities With A Basis Difference Weighted Average Life Of Assets and Liabilities With A Basis Difference Variable Interest Entities [Abstract] Variable Interest Entities [Abstract] Schedule of Variable Interest Entities [Table] Schedule of Variable Interest Entities [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Securitization Vehicles Securitization Vehicles [Member] Securitization Vehicles [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Consolidation adjustments Consolidation, Eliminations [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Securities purchased under agreement to resell Securities Purchased under Agreements to Resell Receivables Receivables Receivables Other Other Assets Total assets Assets Other secured financings Other Secured Financings Other Other Liabilities Total liabilities Liabilities Secured financings eliminated in consolidation Secured financings eliminated in consolidation Secured financings eliminated in consolidation Intercompany payables Intercompany Payables Intercompany Payables Derivative Instruments and Hedging Activities Disclosure [Abstract] Fair Value And Related Number Of Derivative Contracts Categorized By Predominant Risk Exposure Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Unrealized And Realized Gains (Losses) On Derivative Contracts Derivative Instruments, Gain (Loss) [Table Text Block] Remaining Contract Maturity Of Fair Value Of OTC Derivative Assets And Liabilities Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Table Text Block] OTC derivatives by risk exposure and maturity profile. Counterparty Credit Quality With Respect To Fair Value Of OTC Derivatives Assets Counterparty Credit Quality With Respect To Fair Value Of Otc Derivatives Assets [Table Text Block] Counterparty credit quality with respect to the fair value of OTC derivatives assets. Credit Related Derivative Contracts Disclosure of Credit Derivatives [Table Text Block] Derivative Instruments With Contingent Features Derivative Instruments With Contingent Features [Table Text Block] Derivative Instruments With Contingent Features [Table Text Block] Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Shares $1 Par Value Common Stock [Member] Additional Paid-In Capital Additional Paid-in Capital [Member] Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Subtotal Parent [Member] Noncontrolling Interests Noncontrolling Interest [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Cumulative effect of the adoption of accounting standards Cumulative Effect of New Accounting Principle in Period of Adoption Beginning Balance, adjusted Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest, Adjusted Balance Net income Profit Loss Excluding Net Income Loss Attributable To Redeemable Noncontrolling Interests Profit Loss Excluding Net Income Loss Attributable To Redeemable Noncontrolling Interests Other comprehensive loss, net of taxes Other Comprehensive Income (Loss), Net of Tax Contributions from noncontrolling interests Contributions from Noncontrolling Interests Contributions from Noncontrolling Interests Distributions to noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Issuance of shares for HomeFed acquisition Stock Issued During Period, Value, Acquisitions Reversal of cumulative National Beef redeemable noncontrolling interests fair value adjustments prior to deconsolidation Reversal Of Cumulative Redeemable Noncontrolling Interests Fair Value Adjustments Prior To Deconsolidation Reversal Of Cumulative Redeemable Noncontrolling Interests Fair Value Adjustments Prior To Deconsolidation Change in interest in consolidated subsidiary Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Net Share-based compensation expense Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Change in fair value of redeemable noncontrolling interests Change In Fair Value Of Redeemable Noncontrolling Interests Change In Fair Value Of Redeemable Noncontrolling Interests Consolidation of asset management entity Consolidation Of Asset Management Entity Consolidation Of Asset Management Entity Exercise of options to purchase common shares Stock Issued During Period, Value, Stock Options Exercised Purchase of common shares for treasury Treasury Stock, Value, Acquired, Cost Method Dividends Dividends, Common Stock Other Stockholders' Equity, Other Ending Balance Assets And Liabilities Of Consolidated VIEs Consolidated Variable Interest Entities [Table Text Block] Consolidated Variable Interest Entities [Table Text Block] Non-Consolidated Variable Interest Entities Non Consolidated Variable Interest Entities [Table Text Block] Non-consolidated variable interest entities aggregated by principal business activity. Share-based Compensation [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Unusual or Infrequent Item [Axis] Unusual or Infrequent Item, or Both [Axis] Unusual or Infrequent Item [Domain] Unusual or Infrequent Item, or Both [Domain] Future Service Required Future Service Required [Member] Future service required. No Future Service Required No Future Service Required [Member] No future service required. Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Sign-on and Retention Awards Sign-on and Retention Awards [Member] Sign-on and Retention Awards [Member] Restricted Stock Restricted Stock [Member] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Other Shares Issuable Other Shares Issuable [Member] Other Shares Issuable [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Award vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Amortization period Share-Based Compensation Arrangement By Share-Based Payment Award, Amortization Period Share-based Compensation Arrangement by Share-based Payment Award, Amortization Period Share-based compensation Share-based Compensation Tax benefit for issuance of share-based awards Employee Service Share-based Compensation, Tax Benefit from Compensation Expense Total unrecognized compensation cost related to nonvested share-based awards Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized Employee service share-based compensation, unrecognized compensation costs on nonvested awards, weighted average period of recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Restricted shares, nonvested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Restricted shares, vested (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award Equity Instruments Other Than Options, Vested, Number Share-Based Compensation Arrangement By Share-Based Payment Award Equity Instruments Other Than Options, Vested, Number Other shares issuable (in shares) Other shares issuable Other shares issuable Potential maximum increase to common shares outstanding from restricted stock and other shares (in shares) Potential Maximum Increase To Common Shares Outstanding From Restricted Stock And Other Shares Potential Maximum Increase to Common Shares Outstanding from Restricted Stock and Other Shares Restricted cash awards, cost expected to be recognized Restricted Cash Awards, Compensation Cost Not Yet Recognized Restricted Cash Awards, Compensation Cost Not Yet Recognized Restricted cash awards, cost expected to be recognized, period Restricted Cash Awards, Compensation Cost Not Yet Recognized, Period For Recognition Restricted Cash Awards, Compensation Cost Not Yet Recognized, Period For Recognition Exchange-traded Exchange Traded Options [Member] Cleared OTC Cleared OTC [Member] Cleared OTC [Member] Bilateral OTC Bilateral OTC [Member] Bilateral OTC [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Designated as Accounting Hedges Designated as Hedging Instrument [Member] Not Designated as Accounting Hedges Not Designated as Hedging Instrument [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate contracts Interest Rate Contract [Member] Foreign exchange contracts Foreign Exchange Contract [Member] Equity contracts Equity Contract [Member] Commodity contracts Commodity Contract [Member] Credit contracts Credit Contracts [Member] Credit Contracts [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Fair Value, Assets Derivative Asset, Fair Value, Gross Asset Number of Contracts, Assets Derivative Asset, Number of Instruments Held Fair Value, Liabilities Derivative Liability, Fair Value, Gross Liability Number of Contracts, Liabilities Derivative Liability, Number of Instruments Held Amounts offset in Consolidated Statement of Financial Condition, Assets Counterparty/cash-collateral netting, Assets Derivative, Fair Value of Derivative Asset, Amount Netting in Consolidated Statement of Financial Condition Amounts offset in Consolidated Statement of Financial Condition, Liabilities Counterparty/cash-collateral netting, Liabilities Derivative, Fair Value of Derivative Liability, Amount Netting in Consolidated Statement of Financial Condition Net Amounts in Consolidated Statements of Financial Condition Derivative Asset Net Amounts in Consolidated Statements of Financial Condition Derivative Liability Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Corporate equity securities Equity Securities [Member] Corporate debt securities Corporate Debt Securities [Member] Sovereign Obligations [Domain] Sovereign Obligations [Domain] Sovereign Obligations [Domain] CDOs and CLOs Collateralized Debt Obligations and Collateralized Loan Obligations [Member] Collateralized Debt Obligations and Collateralized Loan Obligations [Member] Residential mortgage-backed securities Residential Mortgage Backed Securities [Member] Commercial mortgage-backed securities Commercial Mortgage Backed Securities [Member] Other asset-backed securities Other Asset Backed Securities [Member] Other asset-backed securities. Loans and other receivables Loans and Finance Receivables [Member] Investments at fair value Investments at Fair Value [Member] Investments at Fair Value [Member] FXCM term loan Investment in Senior Secured Term Loan [Member] Investment in Senior Secured Term Loan [Member] Securities purchased under agreements to resell Securities Purchased Under Agreements To Resell [Member] Securities Purchased Under Agreements To Resell [Member] Loans Loans [Member] Derivatives Derivative [Member] Long-term debt Long-term Debt [Member] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Assets: Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Total gains (losses) (realized and unrealized) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Settlements Issuances Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances Net transfers into (out of) Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net Ending Balance Fair value, Assets, change in unrealized gains/(losses) included in earnings relating to instruments still held Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss) Liabilities: Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Beginning Balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability Value Total gains/ losses (realized and unrealized) Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Total gains (losses) (realized and unrealized), included in earnings and OCI Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included In Earnings And Other Comprehensive Income (Loss) Fair Value, Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included In Earnings And Other Comprehensive Income (Loss) Purchases Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Purchases Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales Settlements Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements Issuances Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances Net transfers into (out of) Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net Ending Balance Fair value, Liabilities, change in unrealized gains/(losses) included in earnings relating to instruments still held Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss) Fair value, Liabilities, change in unrealized gains/(losses) included in other comprehensive income relating to instruments still held Fair Value, Liabilities Measured On Recurring Basis, Change In Unrealized Gain (Loss) Included In Other Comprehensive Income Fair Value, Liabilities Measured On Recurring Basis, Change In Unrealized Gain (Loss) Included In Other Comprehensive Income Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block] Guarantees Schedule of Guarantor Obligations [Table Text Block] Revenues Equity Method Investment, Summarized Financial Information, Revenue Income from continuing operations before extraordinary items Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations Net income Equity Method Investment, Summarized Financial Information, Net Income (Loss) Segment Reporting [Abstract] Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Reportable Segments Operating Segments [Member] Consolidation adjustments Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Merchant Banking Merchant Banking Segment [Member] Merchant Banking Segment [Member] Corporate Corporate Segment [Member] LAM and Berkadia Transferred Leucadia Asset Management And Berkadia Transferred [Member] Leucadia Asset Management And Berkadia Transferred [Member] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Parent Company interest Parent Company [Member] Segment Reporting Information [Line Items] Net Revenues Revenues, Net of Interest Expense Consolidated income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Depreciation and amortization Depreciation, Depletion and Amortization Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Table] Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Table] Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Table] Commodity swaps, options and forwards Commodity Swaps Options And Forwards [Member] Commodity swaps options and forwards. Equity swaps and options Equity Swaps And Options [Member] Equity Swaps And Options [Member] Credit default swaps Credit Default Swap [Member] Total return swaps Total Return Swap [Member] Foreign currency forwards, swaps and options Foreign Currency Forwards Swaps And Options [Member] Foreign currency forwards swaps and options. Fixed income forwards Fixed Income Forwards [Member] Fixed income forwards. Interest rate swaps, options and forwards Interest Rate Swaps, Options And Forwards [Member] Interest Rate Swaps, Options And Forwards [Member] Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items] Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items] Remaining Contract Maturity Of Fair Value Of Over Counter Derivative Assets And Liabilities [Line Items] OTC derivative assets having maturity period of 0 to 12 months Otc Derivative Assets Having Maturity Period Of Zero To Twelve Months Over the counter derivative assets having maturity period of zero to twelve months. OTC derivative assets having maturity period of 1 to 5 years Otc Derivative Assets Having Maturity Period Of One To Five Years OTC derivative assets having maturity period of 1 to5 years. OTC derivative assets having maturity period of greater than 5 years Otc Derivative Assets Having Maturity Period Of Greater Than Five Years OTC derivative assets having maturity period of greater than five years. OTC derivative assets cross-maturity netting Otc Derivative Assets Cross Maturity Netting OTC derivative assets cross maturity netting. Total OTC derivative assets, net of cross-maturity netting Consolidated Otc Derivative Assets Net Of Crossmaturity Netting Total OTC derivative assets, net of cross-maturity netting. Cross product counterparty netting Derivative Assets Cross Product Counterparty Netting Derivative Assets Cross Product Counterparty Netting. Total OTC derivative assets included in Trading assets Otc Derivative Assets Included In Financial Instruments Owned OTC Derivative Assets Included In Financial Instruments Owned. OTC derivative liabilities having maturity period of 0 to 12 months Otc Derivative Liabilities Having Maturity Period Of Zero To Twelve Months OTC derivative liabilities having maturity period of zero to twelve months. OTC derivative liabilities having maturity period of 1 to 5 years Otc Derivative Liabilities Having Maturity Period Of One To Five Years OTC derivative liabilities having maturity period of 1 to 5 years. OTC derivative liabilities having maturity period of greater than 5 years Otc Derivative Liabilities Having Maturity Period Of Greater Than Five Years OTC derivative liabilities having maturity period of greater than 5 years. OTC derivative liabilities cross-maturity netting Otc Derivative Liabilities Cross Maturity Netting OTC derivative liabilities cross maturity netting. Total OTC derivative liabilities, net of cross-maturity netting Consolidated Otc Derivative Liabilities Net Of Crossmaturity Netting Total OTC derivative liabilities, net of cross-maturity netting. Cross product counterparty netting Derivative Liabilities Cross Product Counterparty Netting Derivative Liabilities Cross Product Counterparty Netting. Total OTC derivative liabilities included in Trading liabilities OTC Derivative Liabilities Included In Trading Liabilities OTC Derivative Liabilities Included In Trading Liabilities Exchange traded derivative assets and other credit agreements Exchange traded derivative assets and other credit agreements Exchange traded derivative assets and other credit agreements Cash collateral received Cash Collateral Received Cash collateral received that was netted against OTC derivative assets. Exchange traded derivative liabilities and other credit agreements Exchange traded derivative liabilities and other credit agreements Exchange traded derivative liabilities and other credit agreements Cash collateral pledged Cash collateral pledged Cash collateral pledged that was netted against OTC derivative liabilities. Temporary Equity Disclosure [Abstract] Schedule Of Redeemable Noncontrolling Interests Schedule of Redeemable Noncontrolling Interests [Table Text Block] Schedule of Redeemable Noncontrolling Interests [Table Text Block] Investments [Abstract] Schedule of Investments [Table] Schedule of Investments [Table] U.S. government securities US Treasury and Government [Member] Schedule of Investments [Line Items] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Estimated Fair Value Debt Securities, Available-for-sale Level 3 Fair Value, Inputs, Level 3 [Member] Corporate equity securities Non-exchange-traded securities Non Exchange Traded Securities [Member] Non Exchange Traded Securities [Member] Private equity securities Private Equity Securities [Member] Private Equity Securities [Member] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] Price Measurement Input, Offered Price [Member] Transaction level Measurement Input, Transaction Level [Member] Measurement Input, Transaction Level [Member] Underlying stock price Measurement Input, Share Price [Member] Discount rate/yield Measurement Input, Discount Rate [Member] Estimated recovery percentage Measurement Input, Estimated Recovery Percentage [Member] Measurement Input, Estimated Recovery Percentage [Member] Credit spread Credit Spread Option [Member] Constant prepayment rate Measurement Input, Prepayment Rate [Member] Constant default rate Measurement Input, Default Rate [Member] Loss severity Measurement Input, Loss Severity [Member] Cumulative loss rate Measurement Input, Cumulative Loss Rate [Member] Measurement Input, Cumulative Loss Rate [Member] Duration (years) Measurement Input, Expected Term [Member] Revenue growth Measurement Input, Long-term Revenue Growth Rate [Member] Volatility Measurement Input, Price Volatility [Member] Term based on the pay off (years) Measurement Input, Maturity [Member] Spread to 6 month LIBOR Measurement Input, Spread To 6 Month LIBOR [Member] Measurement Input, Spread To 6 Month LIBOR [Member] Default probability Measurement Input, Default Probability [Member] Measurement Input, Default Probability [Member] Basis points upfront Measurement Input, Basis Points [Member] Measurement Input, Basis Points [Member] Equity options Equity Option [Member] Interest rate swaps Interest Rate Swap [Member] Cross currency swaps Currency Swap [Member] Unfunded commitments Unfunded Commitments [Member] Unfunded Commitments [Member] Total return swaps Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Discounted cash flows Discounted Cash Flows [Member] Discounted Cash Flows [Member] Scenario analysis Scenario Analysis [Member] Scenario Analysis [Member] Market approach Valuation, Market Approach [Member] Contingent claims analysis Contingent Claims Analysis [Member] Contingent Claims Analysis [Member] Option model/default rate Option Model / Default Rate [Member] Option Model / Default Rate [Member] Volatility benchmarking Volatility Benchmarking [Member] Volatility Benchmarking [Member] Weighted Average Weighted Average [Member] Trading assets, fair value Trading Assets, At Fair Value Trading Assets, At Fair Value Trading assets, measurement input Trading Assets, Measurement Input Trading Assets, Measurement Input Trading assets, measurement input, term Trading Assets, Measurement Input, Term Trading Assets, Measurement Input, Term Securities purchased under agreements to resell Derivatives Derivative asset, measurement input Derivative Asset, Measurement Input Securities purchased under agreements to resell, measurement input Securities Purchased Under Agreements To Resell, Measurement Input Securities Purchased Under Agreements To Resell, Measurement Input Securities purchased under agreements to resell, measurement input, term Securities Purchased Under Agreements To Resell, Measurement Input, Term Securities Purchased Under Agreements To Resell, Measurement Input, Term Debt instrument, fair value Debt Instrument, Fair Value Disclosure Debt instrument, measurement input Debt Instrument, Measurement Input Derivative liability Derivative liability, measurement input Derivative Liability, Measurement Input Long-term debt, fair value Long-term Debt, Fair Value Long-term debt, measurement input Long-term Debt, Measurement Input Debt Disclosure [Abstract] Short-Term Borrowings Short-term Debt [Text Block] Collateralized Transactions [Abstract] Collateralized Transactions [Abstract] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Table] Corporate equity securities Mortgage- and asset-backed securities Mortgage-Backed Securities and Asset-backed Securities [Member] Mortgage-Backed Securities and Asset-backed Securities [Member] U.S. government and federal agency securities US Government Corporations and Agencies Securities [Member] Municipal securities Municipal Bonds [Member] Sovereign obligations Sovereign Debt Securities [Member] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Securities lending arrangements Securities Loaned, Including Not Subject to Master Netting Arrangement and Assets other than Securities Transferred Repurchase agreements Financial Assets Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement Total Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement Commitments Contingencies And Guarantees [Table] Commitments Contingencies And Guarantees [Table] Commitments Contingencies And Guarantees [Table] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent event Subsequent Event [Member] Jefferies Capital Partners LLC and Its Private Equity Funds Jefferies Capital Partners Llc And Private Equity Funds [Member] Jefferies Capital Partners LLC and Private Equity Funds [Member] Other Investments Other Various Investments [Member] Other Various Investments [Member] Spectrum Brands Spectrum Brands Holdings, Inc. [Member] Spectrum Brands Holdings, Inc. [Member] Jefferies Finance Jefferies Finance Llc [Member] Jefferies Finance, LLC [Member] Berkadia Berkadia [Member] Berkadia [Member] HomeFed Homefed Corporation [Member] HomeFed Corporation - Member Other subsidiaries Other Subisidiaries [Member] Other Subisidiaries [Member] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Standby Letters of Credit Financial Standby Letter of Credit [Member] Commitments Contingencies And Guarantees [Line Items] Commitments Contingencies And Guarantees [Line Items] Commitments Contingencies And Guarantees [Line Items] Equity commitments Equity Commitments Committed equity capitalization. Loan commitments outstanding to clients Outstanding Loan Commitments to Clients Outstanding Loan Commitments to Clients. Line of credit facility, commitment of Jefferies, funded Line of Credit Facility, Commitment Under Joint Venture, Entity Portion, Funded Line of Credit Facility, Commitment Under Joint Venture, Entity Portion, Funded Line of credit facility commitment of Jefferies Line of Credit Facility, Commitment Under Joint Venture, Entity Portion Line of Credit Facility, Commitment Under Joint Venture, Entity Portion Dividend distribution (in shares) Dividend Distribution, Number Of Shares Dividend Distribution, Number Of Shares Fair value of derivative contracts meeting the definition of a guarantee Derivative Contracts Meeting Definition of A Guarantee Derivative Contracts Meeting Definition of A Guarantee Surety policy issued Surety policy issued Reimbursement of losses incurred, maximum percentage Reimbursement Of Losses Incurred, Maximum Percentage Reimbursement of losses incurred, maximum percentage. Aggregate amount of commercial paper outstanding Commercial Paper Aggregate amount of infrastructure improvement bonds outstanding Aggregate Amount Of Infrastructure Improvement Bonds Outstanding Aggregate Amount Of Infrastructure Improvement Bonds Outstanding Letters of credit Letters of Credit Outstanding, Amount Expiration period maximum Expiration Period Expiration Period Statement of Financial Position [Abstract] HomeFed's associated companies HomeFed Associated Companies [Member] HomeFed Associated Companies [Member] RedSky JZ Fulton Holdings, LLC RedSky JZ Fulton Holdings, LLC [Member] RedSky JZ Fulton Holdings, LLC [Member] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Real Estate [Domain] Real Estate [Domain] Hotel Hotel [Member] Office Building Office Building [Member] Equity method investment, ownership percentage Number of separate tax lots Number Of Separate Tax Lots Number Of Separate Tax Lots Number of premier development sites Number Of Premier Development Sites Number Of Premier Development Sites Area of property (up to) Area of Real Estate Property Accounting Policies [Abstract] Supplemental cash flow information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Derivative [Table] Derivative [Table] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Domain] External Credit Rating by Grouping [Domain] Investment Grade External Credit Rating, Investment Grade [Member] Non-investment grade External Credit Rating, Non Investment Grade [Member] Unrated Unrated [Member] Unrated [Member] Credit Derivatives Contract Type [Axis] Credit Derivatives Contract Type [Axis] Credit Derivatives Contract Type [Domain] Credit Derivatives Contract Type [Domain] Index credit default swaps Credit Index Product [Member] Single name credit default swaps Derivative [Line Items] Derivative [Line Items] Notional amount Derivative, Notional Amount Financial Instruments [Table] Financial Instruments [Table] Financial Instruments [Table] Securities or Other Assets Sold under Agreements to Repurchase [Axis] Securities or Other Assets Sold under Agreements to Repurchase [Axis] Assets Sold under Agreements to Repurchase, Type [Domain] Assets Sold under Agreements to Repurchase, Type [Domain] Trading Assets Trading Assets, Excluding Debt and Equity Securities [Member] Trading Liabilities Trading Liabilities [Member] Financial Instruments [Line Items] Financial Instruments [Line Items] Loans and other receivables Fair Value, Option, Credit Risk, Gains (Losses) on Assets Loans Fair Value, Option, Credit Risk, Gains (Losses) on Loans Fair Value, Option, Credit Risk, Gains (Losses) on Loans Loan commitments Fair Value, Option, Credit Risk, Gains (Losses) on Loan Commitments Fair Value, Option, Credit Risk, Gains (Losses) on Loan Commitments Changes in instrument specific credit risk Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, before Tax Other changes in fair value Fair Value, Option, Changes in Fair Value, Gain (Loss) Schedule of Collateralized Financing Transactions Schedule of Collateralized Financing Transactions [Table Text Block] Schedule of Collateralized Financing Transactions [Table Text Block] Summary of Offsetting Assets Offsetting Assets [Table Text Block] Summary of Offsetting Liabilities Offsetting Liabilities [Table Text Block] Investments In Associated Companies [Table] Investments In Associated Companies [Table] Investments In Associated Companies [Table] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Equity Method Investee [Member] Equity Method Investee [Member] Linkem Linkem [Member] Linkem [Member] Investments In Associated Companies [Line Items] Investments In Associated Companies [Line Items] Percentage of ownership upon conversion of note Ownership Percentage Upon Conversion Of Preferred Shares Ownership Percentage Upon Conversion of Preferred Shares Equity method investment, voting percentage Equity Method Investment, Voting Percentage The voting percentage of common stock or equity participation in the investee accounted for under the equity method of accounting. Shareholder loans principal outstanding Equity Method Investment, Shareholder Loans To Investee, Principal Outstanding Equity Method Investment, Shareholder Loans To Investee, Principal Outstanding Shareholder loans interest rate Related Party Transaction, Rate Disposal Groups, Including Discontinued Operations [Table] Disposal Groups, Including Discontinued Operations [Table] Product and Service [Axis] Product and Service [Axis] Product and Service [Domain] Product and Service [Domain] Beef processing services Beef Processing Services [Member] Beef Processing Services [Member] Interest income Interest Revenue [Member] Interest Revenue [Member] Other Product and Service, Other [Member] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Revenues Disposal Group, Including Discontinued Operation, Revenue Expenses: Disposal Group, Including Discontinued Operation, Expenses [Abstract] Disposal Group, Including Discontinued Operation, Expenses [Abstract] Compensation and benefits Disposal Group, Including Discontinued Operation, Compensation And Benefits Disposal Group, Including Discontinued Operation, Compensation And Benefits Cost of sales Disposal Group, Including Discontinued Operation, Costs of Goods Sold Interest expense Disposal Group, Including Discontinued Operation, Interest Expense Depreciation and amortization Disposal Group, Including Discontinued Operation, Depreciation and Amortization Selling, general and other expenses Disposal Group, Including Discontinued Operation, General and Administrative Expense Total expenses Disposal Group, Including Discontinued Operation, Operating Expense Income from discontinued operations before income taxes Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, before Income Tax Income tax provision Discontinued Operation, Tax Effect of Income (Loss) from Discontinued Operation During Phase-out Period Income from discontinued operations, net of income tax provision Discontinued Operation, Income (Loss) from Discontinued Operation During Phase-out Period, Net of Tax Investment in FXCM Investment in FXCM [Member] Investment in FXCM [Member] Investments In Associated Companies [Line Items] Earnings Per Share [Abstract] Common Share and Earnings Per Common Share Earnings Per Share [Text Block] Income Statement [Abstract] Gain on disposal of discontinued operations, income tax provision Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] Bank loans Line of Credit Line of Credit [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Floating rate puttable notes Floating Rate Puttable Notes [Member] Floating Rate Puttable Notes [Member] Jefferies Group Credit Facility Jefferies Group Credit Facility [Member] Jefferies Group Credit Facility [Member] Intraday Credit Facility Intraday Credit Facility [Member] Intraday Credit Facility [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] Federal funds effective rate Federal Funds Effective Rate [Member] Federal Funds Effective Rate [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] Short-term borrowings Interest rates on short-term borrowings outstanding Short-term Debt, Weighted Average Interest Rate, at Point in Time Short-term borrowings matured during period Debt Instrument, Face Amount Credit facility maximum amount Line of Credit Facility, Maximum Borrowing Capacity Debt instrument, basic spread on variable rate Debt Instrument, Basis Spread on Variable Rate Discontinued Operations Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Net unrealized holding gains (losses) on investments arising during the period, tax provision (benefit) Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax Less: reclassification adjustment for net (gains) losses included in net income (loss), tax provision (benefit) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Net change in unrealized holding gains (losses) on investments, tax provision (benefit) Other Comprehensive Income (Loss), Securities, Available-for-sale, Tax Net unrealized foreign exchange gains (losses) arising during the period, tax provision (benefit) Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax Less: reclassification adjustment for foreign exchange (gains) losses included in net income (loss), tax provision (benefit) Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Tax Net change in unrealized foreign exchange gains (losses), tax provision (benefit) Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Net unrealized gains (losses) on instrument specific credit risk arising during the period, tax provision (benefit) Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Unrealized Gain (Loss) Arising During Period, Tax Less: reclassification adjustment for instrument specific credit risk (gains) losses included in net income (loss), tax provision (benefit) Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, Reclassification Adjustment from AOCI for Derecognition, Tax Net change in unrealized instrument specific credit risk gains (losses), tax provision (benefit) Other Comprehensive Income (Loss), Financial Liability, Fair Value Option, after Reclassification Adjustment, Tax Net unrealized gains (losses) on cash flow hedges arising during the period, net of income tax provision (benefit) of $(86) and $1,234 Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Less: reclassification adjustment for cash flow hedges (gains) losses included in net income (loss), tax provision (benefit) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Net change in unrealized cash flow hedges gains (losses), tax provision (benefit) Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Net pension gains (losses) arising during the period, tax provision (benefit) Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, Tax Less: reclassification adjustment for pension (gains) losses included in net income (loss), tax provision (benefit) Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Net change in pension liability, tax provision (benefit) Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Offsetting [Abstract] Securities borrowing arrangements, Assets Offsetting Securities Borrowed [Abstract] Gross Amounts Securities Borrowed, Gross Netting in Consolidated Statements of Financial Condition Securities Borrowed, Liability Net Amounts in Consolidated Statements of Financial Condition Securities Borrowed Additional Amounts Available for Setoff Securities Borrowed, Collateral, Obligation to Return Cash Available Collateral Securities Borrowed, Collateral, Obligation to Return Securities Net Amount Securities Borrowed, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Reverse repurchase agreements, Assets Offsetting Securities Purchased under Agreements to Resell [Abstract] Gross Amounts Securities Purchased under Agreements to Resell, Gross Netting in Consolidated Statements of Financial Condition Securities Purchased under Agreements to Resell, Liability Net Amounts in Consolidated Statements of Financial Condition Additional Amounts Available for Setoff Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Cash Available Collateral Securities Purchased under Agreements to Resell, Collateral, Obligation to Return Securities Net Amount Securities Purchased under Agreements to Resell, Amount Offset Against Collateral Securities lending arrangements, Liabilities Offsetting Securities Loaned [Abstract] Gross Amounts Securities Loaned, Gross Netting in Consolidated Statements of Financial Condition Securities Loaned, Asset Net Amounts in Consolidated Statements of Financial Condition Securities Loaned Additional Amounts Available for Setoff Securities Loaned, Collateral, Right to Reclaim Cash Available Collateral Securities Loaned, Collateral, Right to Reclaim Securities Net Amount Securities Loaned, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Repurchase agreements, Liabilities Offsetting Securities Sold under Agreements to Repurchase [Abstract] Gross Amounts Securities Sold under Agreements to Repurchase, Gross Netting in Consolidated Statements of Financial Condition Securities Sold under Agreements to Repurchase, Asset Net Amounts in Consolidated Statements of Financial Condition Securities Sold under Agreements to Repurchase Additional Amounts Available for Setoff Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Cash Available Collateral Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities Net Amount Securities Sold under Agreements to Repurchase, Amount Offset Against Collateral Securities borrowing agreement, subject to review Securities Borrowed Asset, Net, Subject to Review Securities Borrowed Asset, Net, Subject to Review Securities borrowing agreement, collateral received, subject to review Securities Borrowed Asset, Collateral Received, Subject to Review Securities Borrowed Asset, Collateral Received, Subject to Review Repurchase agreement, net amount, subject to review Securities Sold under Agreements to Repurchase, Net Amount, Subject to Review Securities Sold under Agreements to Repurchase, Net Amount, Subject to Review Repurchase agreements, collateral pledged, subject to review Securities Sold under Agreements to Repurchase, Collateral Pledged, Subject to Review Securities Sold under Agreements to Repurchase, Collateral Pledged, Subject to Review Investments, Debt and Equity Securities [Abstract] Other investment not readily marketable, fair value Other Investment Not Readily Marketable, Fair Value Investments impairment Other than Temporary Impairment Losses, Investments Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Interest rate swaps Parent Company Subsidiaries Subsidiaries [Member] 5.50% Senior Notes due October 18, 2023 Five Point Five Zero Percent Senior Notes Due Two Thousand Twenty Three [Member] Five Point Five Zero Percent Senior Notes Due Two Thousand Twenty Three [Member] 6.625% Senior Notes due October 23, 2043 Six Point Six Two Five Percent Senior Notes Due Two Thousand Forty Three [Member] Six Point Six Two Five Percent Senior Notes Due Two Thousand Forty Three [Member] 8.50% Senior Notes, due July 15, 2019 Eight Point Five Percentage Senior Notes Due Two Thousand Nineteen [Member] 8.5% Senior Notes, due 2019. 2.375% Euro Medium Term Notes, due May 20, 2020 Two Point Three Seven Five Percentage Euro Medium Term Notes Due Two Thousand Twenty [Member] 2.375% Euro Senior Notes, due Two Thousand Twenty [Member] 6.875% Senior Notes, due April 15, 2021 Six Point Eight Seven Five Percentage Senior Notes Due Two Thousand Twenty One [Member] 6.875% Senior Note, due 2021. 2.25% Euro Medium Term Notes, due July 13, 2022 Two Point Two Five Percentage Euro Medium Term Notes Due Two Thousand Twenty Two [Member] Two Point Two Five Percentage Euro Medium Term Notes Due Two Thousand Twenty Two [Member] 5.125% Senior Notes, due January 20, 2023 Five Point One Two Five Percentage Senior Notes Due Two Thousand Twenty Three [Member] Five Point One Two Five Percentage Senior Notes Due Two Thousand Twenty Three [Member] 1.00% Euro Medium Term Notes, due July 19, 2024 One Percentage Euro Medium Term Notes Due 2024 [Member] One Percentage Euro Medium Term Notes Due 2024 [Member] 4.85% Senior Notes, due January 15, 2027 Four Point Eight Five Percentage Senior Notes Due Two Thousand Twenty Seven [Member] Four Point Eight Five Percentage Senior Notes Due Two Thousand Twenty Seven [Member] 6.45% Senior Debentures, due June 8, 2027 Six Point Four Five Percentage Senior Debentures Due Two Thousand Twenty Seven [Member] Six Point Four Five Percentage Senior Debentures Due Two Thousand Twenty Seven [Member] 4.15% Senior Notes, due January 23, 2030 Four Point One Five Percentage Senior Notes Due Two Thousand Thirty [Member] Four Point One Five Percentage Senior Notes Due Two Thousand Thirty 6.25% Senior Debentures, due January 15, 2036 Six Point Two Five Percentage Senior Debentures Due Two Thousand Thirty Six [Member] 6.25% Senior Debentures, due 2036. 6.50% Senior Notes, due January 20, 2043 Six Point Five Zero Percentage Senior Notes Due Two Thousand Forty Three [Member] Six Point Five Zero Percentage Senior Notes Due Two Thousand Forty Three [Member] Structured notes Structured Notes [Member] Structured Notes [Member] Revolving Credit Facility Revolving Credit Facility [Member] Foursight Capital Credit Facilities Foursight Credit Facilities [Member] Foursight Credit Facilities [Member] HomeFed EB-5 Program debt HomeFed EB-5 Program Debt [Member] HomeFed EB-5 Program Debt [Member] Other Other Long Term Debt [Member] Other Long-Term Debt [Member] Debt Instrument [Line Items] Interest rate Debt Instrument, Interest Rate, Stated Percentage Principal Outstanding Principal Outstanding Principal Outstanding Gain (loss) associated with an interest rate swap based on its designation as a fair value hedge Gain (Loss) on Fair Value Hedges Recognized in Earnings Net Capital Requirements [Abstract] Net Capital Requirements [Abstract] Net Capital Requirements [Table] Net Capital Requirements [Table] Net Capital Requirements [Table] Jefferies LLC Jefferies LLC [Member] Jefferies LLC [Member] Net Capital Requirements [Line Items] Net Capital Requirements [Line Items] Net Capital Requirements [Line Items] Net capital Net Capital Excess net capital Alternative Excess Net Capital Net Capital Requirements Regulatory Capital Requirements Disclosure [Text Block] Regulatory capital requirements disclosure. Revenue from Contract with Customer [Abstract] Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] Variable Interest Entities Variable Interest Entities Disclosure [Text Block] Variable Interest Entities Disclosure [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Revenue related to performance obligation satisfied Contract With Customer, Revenue Related to Performance Obligations Satisfied in Previous Periods Contract With Customer, Revenue Related to Performance Obligations Satisfied in Previous Periods Revenue associated with distribution services, a portion of which related to prior period Revenues Associated With Distribution Services Revenues Associated With Distribution Services Receivables related to revenue from contracts with customers Contract with Customer, Asset, Net Deferred revenue Contract with Customer, Liability Deferred revenue, revenue recognized Contract with Customer, Liability, Revenue Recognized Capitalized contract cost Capitalized Contract Cost, Net Expenses related to capitalized costs to fulfill a contract Capitalized Contract Cost, Amortization Loans to and Investments in Associated Companies Equity Method Investments and Joint Ventures Disclosure [Text Block] Equities Equities [Member] Equities [Member] Fixed Income Fixed Income Services [Member] Fixed Income Services [Member] Investment Banking - Capital markets Investment Banking, Capital Markets [Member] Investment Banking, Capital Markets [Member] Investment Banking - Advisory Investment Banking, Advisory [Member] Investment Banking, Advisory [Member] Asset Management Asset Management Services [Member] Asset Management Services [Member] Manufacturing revenues Manufacturing Revenues [Member] Manufacturing Revenues [Member] Oil and gas revenues Oil And Gas Production And Development Revenues [Member] Oil And Gas Production And Development Revenues [Member] Other revenues Revenue From Contract With Customer, Miscellaneous [Member] Revenue From Contract With Customer, Miscellaneous [Member] Consolidation adjustments Segment Reconciling Items [Member] Corporate Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] Americas Americas [Member] Europe, Middle East and Africa EMEA [Member] Asia Asia [Member] Revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Transfers of assets from Level 2 to Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Transfers Into Level 3 Transfers of assets from Level 3 to Level 2 Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3 Transfers of liabilities from Level 2 to Level 3 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers Into Level 3 Transfers of liabilities from Level 3 to Level 2 Fair Value, Measurement with Unobservable Inputs Reconciliation, Liability, Transfers out of Level 3 Net gains (losses) on Level 3 assets (realized and unrealized) Net gains (losses) on Level 3 liabilities (realized and unrealized) Net gains (losses) on Level 3 liabilities (realized and unrealized), included in earnings and OCI Excluded assets from unobservable quantitative information Excluded Securities from Unobservable Quantitative Information, Assets Excluded Securities from Unobservable Quantitative Information, Assets Excluded liabilities from unobservable quantitative information Excluded Securities from Unobservable Quantitative Information, Liabilities Excluded Securities from Unobservable Quantitative Information, Liabilities Securities or Other Assets Sold under Agreements to Repurchase, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Assets Sold under Agreements to Repurchase, Maturity Period [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Overnight and Continuous Maturity Overnight [Member] Up to 30 Days Maturity Less than 30 Days [Member] 30 to 90 Days Maturity 30 to 90 Days [Member] Greater than 90 Days Maturity Greater than 90 Days [Member] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Axis] Retirement Plan Sponsor Location [Domain] Retirement Plan Sponsor Location [Domain] German Plan Foreign Plan [Member] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Pension Plan Pension Plan [Member] Jefferies Bache Limited Jefferies Bache Limited [Member] Jefferies Bache Limited [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Payment to transfer defined benefit obligation and insurance contracts Defined Benefit Plan, Payment To Transfer Defined Benefit Obligation And Insurance Contracts Defined Benefit Plan, Payment To Transfer Defined Benefit Obligation And Insurance Contracts Reclassification adjustment from AOCI related to pension plan Other Comprehensive (Income) Loss, Other Pension Adjustment, Reclassification Adjustment From AOCI, After Tax Other Comprehensive (Income) Loss, Other Pension Adjustment, Reclassification Adjustment From AOCI, After Tax Securitization Activities [Abstract] Securitization Activities [Abstract] Securitization Activities [Table] Securitization Activities [Table] Securitization Activities [Table] CLOs Collateralized Loan Obligations [Member] Consumer and other loans Consumer and Other Loans [Member] Consumer and Other Loans [Member] Securitization Activities [Line Items] Securitization Activities [Line Items] U.S. government agency residential mortgage-backed securities Rmbs Securitization Assets Represents unpaid principal amount of assets in residential mortgage backed securitization vehicles at the balance sheet date. U.S. government agency commercial mortgage-backed securities Cmbs Securitization Assets Represents unpaid principal amount of assets in commercial mortgage backed securitization vehicles at the balance sheet date. CLOs Collateralized Loan Obligations Securitization Assets Collateralized Loan Obligations Securitization Assets Consumer and other loans Consumer and Other Loans Securitization Assets Consumer and Other Loans Securitization Assets Retained Interests Retained Interest, Fair Value Disclosure Revenues from Contracts with Customers Revenue from Contract with Customer [Text Block] Loans and Leases Receivable Disclosure [Table] Loans and Leases Receivable Disclosure [Table] Change in Accounting Estimate by Type [Axis] Change in Accounting Estimate by Type [Axis] Change in Accounting Estimate, Type [Domain] Change in Accounting Estimate, Type [Domain] Reclassified presentation of certain other fees Reclassified Presentation Of Certain Other Fees [Member] Reclassified Presentation Of Certain Other Fees [Member] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Credit Concentration Risk Credit Concentration Risk [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Domain] Concentration Risk Benchmark [Domain] Loans Receivable Loans Receivable [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Prime Prime [Member] Near-Prime Near-Prime [Member] Near-Prime [Member] Subprime Subprime [Member] Foursight Capital Foursight Capital [Member] Foursight Capital [Member] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Automobile Loan Automobile Loan [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Iowa Premium Iowa Premium [Member] Iowa Premium [Member] Commissions and other fees Commission And Other Fees [Member] Commission And Other Fees [Member] Loans and Leases Receivable Disclosure [Line Items] Loans and Leases Receivable Disclosure [Line Items] Revenues Revenues Receivables from brokers, dealers and clearing organizations Receivables from Brokers-Dealers and Clearing Organizations Receivables from customers of securities operations Receivables from Customers Loans and Leases Receivable, Gross Loans and Leases Receivable, Gross Concentration risk, percentage Concentration Risk, Percentage Payables to brokers, dealers and clearing organizations Payables to Broker-Dealers and Clearing Organizations Payables to customers of securities operations Payables to Customers Non-cash investing activities related to the issuance of common stock for acquisition Non-cash Investing Activities, Issuance Of Common Stock Related To Acquisition Non-cash Investing Activities, Issuance Of Common Stock Related To Acquisition Membership Interest Purchase Agreement, Aggregate Ownership Interests To Purchase Membership Interest Purchase Agreement, Aggregate Ownership Interests To Purchase Membership Interest Purchase Agreement, Aggregate Ownership Interests To Purchase Cash paid during the year for: Supplemental Cash Flow Information [Abstract] Interest Interest Paid, Excluding Capitalized Interest, Operating Activities Income tax payments (refunds), net Income Taxes Paid, Net Membership Interest Purchase Agreement, Proportionate Share Membership Interest Purchase Agreement, Proportionate Share Membership Interest Purchase Agreement, Proportionate Share Schedule Of Commitments And Guarantee Obligations [Table] Schedule Of Commitments And Guarantee Obligations [Table] Schedule Of Commitments And Guarantee Obligations [Table] Equity commitments Equity Commitments [Member] Equity commitments. Loan commitments Loan Commitments [Member] Loan commitments. Underwriting commitments Underwriting Commitments [Member] Underwriting Commitments [Member] Forward starting reverse repos Forward Starting Reverse Repos [Member] Forward Starting Reverse Repos [Member] Forward starting repos Forward Starting Repos [Member] Forward Starting Repos [Member] Other unfunded commitments Other Unfunded Commitments [Member] Other unfunded commitments [Member] Forward starting securities purchased under agreements to resell settled Forward Starting Securities Purchased Under Agreements To Resell Settled [Member] Forward Starting Securities Purchased Under Agreements To Resell Settled [Member] Forward starting securities sold under agreements to repurchase settled Forward Starting Securities Sold Under Agreements To Repurchase Settled [Member] Forward Starting Securities Sold Under Agreements To Repurchase Settled [Member] Commitments And Guarantee Obligations [Line Items] Commitments And Guarantee Obligations [Line Items] Commitments And Guarantee Obligations [Line Items] 2019 Contractual Obligation, Future Minimum Payments Due, Remainder of Fiscal Year 2020 Contractual Obligation, Due in Second Year 2021 and 2022 Contractual Obligation, Due In Third And Fourth Years Commitments and guarantees expected to be due within 3 to 4 fiscal years. These may include, equity, loan, mortgage-related and underwriting commitments, derivative guarantees, etc. 2023 and 2024 Contractual Obligation, Due In Fifth And Sixth Years Commitments and guarantees expected to be due within 5 to 6 fiscal years. These may include, equity, loan, mortgage-related and underwriting commitments, derivative guarantees, etc. 2025 and Later Contractual Obligation, Due In Seventh Year And Thereafter Commitments and guarantees expected to be due within 7 fiscal years and thereafter. These may include, equity, loan, mortgage-related and underwriting commitments and derivative guarantees, etc. Maximum Payout Contractual Obligation Guarantor obligation settled period Repos Obligation Settlement Period Repos Obligation Settlement Period Income Taxes Income Tax Disclosure [Text Block] Activity Related To Securitizations Accounted For As Sales Summary Of Securitization Arrangements Activity [Table Text Block] Tabular disclosure of the amount of financial assets securitized, proceeds and net revenues and cash flows received from retained interests. Summary Of Retained Interests In SPEs Securitization Activities And Variable Interest Entity [Table Text Block] Total information regarding securitization vehicles to which the Company, acting as transferor, have transferred assets and for which the Company received sale accounting treatment. Principal transactions Principal Transactions Revenue [Member] Principal Transactions Revenue [Member] Investment banking Investment Banking [Member] Investment Banking [Member] Revenues: Revenues [Abstract] Revenues Interest expense Interest Expense Net revenues Expenses: Costs and Expenses [Abstract] Compensation and benefits Labor and Related Expense Cost of sales Cost of Goods and Services Sold Floor brokerage and clearing fees Floor Brokerage, Exchange and Clearance Fees Selling, general and other expenses General and Administrative Expense Total expenses Costs and Expenses Income (loss) from continuing operations before income taxes and income related to associated companies Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income related to associated companies Income (Loss) from Equity Method Investments Income from continuing operations before income taxes Income tax provision (benefit) Income from continuing operations Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Income from discontinued operations, net of income tax provision of $0, $0, $0 and $47,045 Gain on disposal of discontinued operations, net of income tax provision of $0, $0, $0 and $229,553 Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net (income) loss attributable to the noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Net (income) loss attributable to the redeemable noncontrolling interests Net Income (Loss) Attributable to Redeemable Noncontrolling Interest Preferred stock dividends Preferred Stock Dividends, Income Statement Impact Net income attributable to Jefferies Financial Group Inc. common shareholders Net Income (Loss) Attributable to Parent Basic earnings per common share attributable to Jefferies Financial Group Inc. common shareholders: Earnings Per Share, Basic [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Basic Share Income from discontinued operations (in dollars per share) Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share Gain on disposal of discontinued operations (in dollars per share) Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Basic Share Net income (in dollars per share) Earnings Per Share, Basic Diluted earnings per common share attributable to Jefferies Financial Group Inc. common shareholders: Earnings Per Share, Diluted [Abstract] Income from continuing operations (in dollars per share) Income (Loss) from Continuing Operations, Per Diluted Share Income from discontinued operations (in dollars per share) Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share Gain on disposal of discontinued operations (in dollars per share) Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax, Per Diluted Share Net income (in dollars per share) Earnings Per Share, Diluted Amounts attributable to Jefferies Financial Group Inc. common shareholders: Net Income (Loss) Attributable to Parent [Abstract] Income from continuing operations, net of taxes Income (Loss) from Continuing Operations, Net of Tax, Attributable to Parent Income from discontinued operations, net of taxes Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Gain on disposal of discontinued operations, net of taxes Discontinued Operation, Gain (Loss) On Disposal Of Discontinued Operation, Net Of Tax, Attributable To Parent Discontinued Operation, Gain (Loss) On Disposal Of Discontinued Operation, Net Of Tax, Attributable To Parent Earnings Per Share [Table] Earnings Per Share [Table] Earnings Per Share [Table] Restricted Stock with Future Service Required Restricted Stock With Future Service Required [Member] Restricted Stock With Future Service Required [Member] Restricted Stock Units with No Future Service Required Restricted Stock Units With No Future Service Required [Member] Restricted Stock Units With No Future Service Required [Member] Stock options Employee Stock Option [Member] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Senior Executive Compensation Plan Senior Executive Compensation Plan [Member] Senior Executive Compensation Plan [Member] Earnings Per Share [Line Items] Earnings Per Share [Line Items] Numerator for earnings per share: Earnings Per Share Reconciliation [Abstract] Net income attributable to Jefferies Financial Group Inc. common shareholders Allocation of earnings to participating securities Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Net income attributable to Jefferies Financial Group Inc. common shareholders for basic earnings per share Net Income (Loss) Available to Common Stockholders, Basic Adjustment to allocation of earnings to participating securities related to diluted shares Undistributed Earnings, Diluted Mandatorily redeemable convertible preferred share dividends Convertible Preferred Dividends, Net of Tax Net income attributable to Jefferies Financial Group Inc. common shareholders for diluted earnings per share Net Income (Loss) Available to Common Stockholders, Diluted Denominator for earnings per share: Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Weighted average common shares outstanding Weighted Average Common Shares Outstanding Weighted Average Common Shares Outstanding Weighted average shares of restricted stock outstanding with future service required Weighted Average Number of Shares, Restricted Stock Weighted average RSUs outstanding with no future service required (in shares) Weighted Average Number Of Shares, Restricted Stock Units Weighted Average Number Of Shares, Restricted Stock Units Denominator for basic earnings per share – weighted average shares Weighted Average Number of Shares Outstanding, Basic Dilutive effect of share-based payment awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Mandatorily redeemable convertible preferred shares (in shares) Incremental Common Shares Attributable to Redeemable Convertible Preferred Shares Incremental Common Shares Attributable to Redeemable Convertible Preferred Shares Denominator for diluted earnings (loss) per share (in shares) Weighted Average Number of Shares Outstanding, Diluted Weighted average shares of participating securities (in shares) Incremental Common Shares Attributable to Participating Nonvested Shares with Non-forfeitable Dividend Rights Commitments, Contingencies And Guarantees Commitments Contingencies and Guarantees [Text Block] Share repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Stock repurchased during period (in shares) Stock Repurchased During Period, Shares Stock repurchased during period Stock Repurchased During Period, Value Remaining authorized repurchase amount Stock Repurchase Program, Remaining Authorized Repurchase Amount Number of shares authorized to be repurchased Stock Repurchase Program, Number of Shares Authorized to be Repurchased ASSETS Assets [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value