Document And Entity Information Note To Financial Statement Details Textual Note 4 - Earnings Per Share Note 6 - Financial Instruments and Fair Value Note 7 - Segment Information Note 10 - Revenue Note 11 - Shareholders' Equity Note 4 - Earnings Per Share - Earnings Per Share Calculation (Details) Note 4 - Earnings Per Share - Anti-dilutive Securities (Details) Note 6 - Financial Instruments and Fair Value - Pre-tax Effect of Interest Rate Swaps (Details) Note 7 - Segment Information - Segment Reporting Information (Details) Income Tax Disclosure [Text Block] Note 10 - Revenue - Disaggregated Revenue by Revenue Source (Details) Note 11 - Shareholders' Equity - Schedule of Shareholders' Equity (Details) Notes To Financial Statements Stock-based compensation expense related to stock options and employee stock purchases Other assets, net Notes To Financial Statements [Abstract] us-gaap_LiabilitiesCurrent Total current liabilities Revenues from external customers us-gaap_Revenues Total revenue New and Used Commercial Vehicle [Member] Represents the information pertaining to new and used commercial vehicle. Auction Rate Securities [Member] rusha_CostOfRevenueLeaseAndRental Lease and rental The aggregate cost related to the lease and rental service. Long-lived assets held for sale, fair value Finance and Insurance [Member] Represents the information pertaining to finance and insurance. Components of ERP Platform Rquired Replacement [Member] Represents the components of ERP Platform that will require replacement. Floor plan notes payable Amounts borrowed to finance the purchase of new and used commercial vehicle inventory. us-gaap_GoodwillAndIntangibleAssetImpairment Goodwill and Intangible Asset Impairment, Total Commercial Vehicle Repair Service [Member] Represents the information pertaining to commercial vehicle repair service. Investments Parts [Member] Represents the information pertaining to parts. Commercial Vehicle [Member] Represents the information pertaining to commercial vehicle. Depreciation and amortization us-gaap_DepreciationDepletionAndAmortization Draws on floor plan notes payable – trade, net rusha_IncreaseDecreaseInFloorPlanNotesPayableTradeNet Increase or decrease in amounts borrowed to finance the purchase of new and used commercial vehicle inventory. Draws on floor plan notes payable – non-trade, net The net change during the reporting period in commercial vehicle floor plan due by the reporting entity. Current maturities of long-term debt Insurance [Member] Represents the information pertaining to insurance service. Current maturities of capital lease obligations us-gaap_AssetsCurrent Total current assets Stockholders' Equity Note Disclosure [Text Block] Treasury stock (in shares) Assets held for sale Common stock, par value $.01 per share; 60,000,000 Class A shares and 20,000,000 Class B shares authorized; 30,502,338 Class A shares and 8,358,525 Class B shares outstanding in 2018; and 31,345,116 Class A shares and 8,469,427 Class B shares outstanding in 2017 Financial Instruments [Domain] Adjustments to reconcile net income to net cash provided by operating activities: Common stock, authorized (in shares) Financial Instrument [Axis] Common stock, par value (in dollars per share) Accrued expenses Product and Service [Axis] Product and Service [Domain] Proceeds from the sale of property and equipment Preferred stock, par value $.01 per share; 1,000,000 shares authorized; 0 shares outstanding in 2018 and 2017 Interest us-gaap_PolicyTextBlockAbstract Accounting Policies Preferred stock, authorized (in shares) Lease and rental Inventories, net Preferred stock, par value (in dollars per share) us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Acquisition of property and equipment Effect of dilutive securities– Employee and director stock options and restricted share awards (in shares) Assets acquired under capital leases Weighted average shares outstanding: Income taxes, net of refunds Product and Service, Other [Member] Trade accounts payable Current liabilities: Truck Segment [Member] Represents the truck segment. Change in customer deposits us-gaap_IncreaseDecreaseInCustomerDeposits Supplemental disclosure of cash flow information: Segment assets us-gaap_Assets Total assets Note receivable affiliate Other Assets Disclosure [Text Block] us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total Cash flows from operating activities: us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1 Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Schedule of Segment Reporting Information, by Segment [Table Text Block] Statement [Line Items] us-gaap_NumberOfOperatingSegments Number of Operating Segments Accounts receivable, net us-gaap_NumberOfReportableSegments Number of Reportable Segments Revenues: Finite-Lived Intangible Assets by Major Class [Axis] Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Finite-Lived Intangible Assets, Major Class Name [Domain] Additional paid-in capital Shareholders’ equity: Segment Reporting Disclosure [Text Block] Equity Award [Domain] Current assets: Customer deposits Numerator for basic and diluted earnings per share – Net income available to common shareholders Fair Value Disclosures [Text Block] Award Type [Axis] Net income Net income Restricted Stock Units (RSUs) [Member] us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash provided by financing activities rusha_NumberOfRealEstatePropertiesPutBackIntoService Number of Real Estate Properties Put Back into Service Represents the number of real estate properties previously classified as "held for sale" are put back into service during the period. Segment operating income (loss) us-gaap_OperatingIncomeLoss Operating income Employee Stock Option [Member] us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by operating activities us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities Prepaid expenses and other Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block] us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease Net increase in cash and cash equivalents Total cost of products sold rusha_RealEstatePreviouslyHeldForSalePutBackIntoService Real Estate Previously Held-for-sale Put Back Into Service Represents the fair value of real estate previously held-for-sale that are put back into service during the period. us-gaap_GrossProfit Gross profit Cost of products sold us-gaap_IndefiniteLivedFranchiseRights Indefinite-Lived Franchise Rights Commitments and Contingencies Disclosure [Text Block] Property and equipment, net Goodwill, net us-gaap_PaymentsOfDividends Payments of cash dividends Cost of products sold: Cash flows from investing activities: us-gaap_PaymentsForRepurchaseOfCommonStock Common stock repurchased us-gaap_IncomeTaxExpenseBenefitContinuingOperationsAdjustmentOfDeferredTaxAssetLiability Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability us-gaap_AvailableForSaleSecuritiesDebtSecurities Debt Securities, Available-for-sale, Total Earnings per common share: Retained Earnings [Member] Earnings Per Share [Text Block] Revenue Treasury Stock [Member] Proceeds from issuance of shares relating to employee stock options and employee stock purchases Additional Paid-in Capital [Member] Common Stock [Member] us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments Income before taxes Provision for income taxes Change in accrued expenses us-gaap_IncreaseDecreaseInAccruedLiabilities Equity Components [Axis] Equity Component [Domain] rusha_NumberOfRealEstatePropertiesSoldDuringPeriod Number of Real Estate Properties Sold During Period The number of real estate properties sold during the period. us-gaap_RealEstateHeldforsale Real Estate Held-for-sale rusha_RealEstateSoldFairValue Real Estate, Sold, Fair Value The fair value amount of investments in land and buildings sold, excluding real estate considered to be inventory of the entity. us-gaap_IncomeTaxExaminationYearUnderExamination Income Tax Examination, Year under Examination Segment income (loss) before taxes us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest Aftermarket Products and Services [Member] Information related to aftermarket products and services. Change in trade accounts payable us-gaap_IncreaseDecreaseInAccountsPayableTrade us-gaap_PaymentsOfDebtIssuanceCosts Debt issuance costs Cash and cash equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period State and Local Jurisdiction [Member] Income Tax Authority, Name [Axis] Income Tax Authority, Name [Domain] Internal Revenue Service (IRS) [Member] Income Tax Authority [Axis] Income Tax Authority [Domain] Disaggregation of Revenue [Table Text Block] us-gaap_AllocatedShareBasedCompensationExpense Allocated Share-based Compensation Expense, Total Domestic Tax Authority [Member] us-gaap_RepaymentsOfLongTermDebt Principal payments on long-term debt us-gaap_RepaymentsOfLongTermCapitalLeaseObligations Principal payments on capital lease obligations Revenue from Contract with Customer [Text Block] Amendment Flag us-gaap_UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Accounting Policies [Abstract] us-gaap_OpenTaxYear Open Tax Year Comprehensive income Selling, General and Administrative Expenses [Member] Dividends declared per common share (in dollars per share) Common Stock, Dividends, Per Share, Declared us-gaap_GainLossOnSaleOfPropertyPlantEquipment Gain on sale of property and equipment us-gaap_SharesOutstanding Balance (in shares) Balance (in shares) Common stock, outstanding (in shares) Preferred stock, outstanding (in shares) us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued Unrecognized Tax Benefits, Income Tax Penalties Accrued us-gaap_UnrecognizedTaxBenefitsInterestOnIncomeTaxesAccrued Unrecognized Tax Benefits, Interest on Income Taxes Accrued Current Fiscal Year End Date Proceeds from long-term debt us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets Change in prepaid expenses and other, net Document Fiscal Period Focus Earliest Tax Year [Member] Document Fiscal Year Focus Latest Tax Year [Member] Document Period End Date Income Statement Location [Axis] Income Statement Location [Domain] Entity Emerging Growth Company Document Type Tax Period [Domain] Entity Small Business Document Information [Line Items] Document Information [Table] Tax Period [Axis] Entity Filer Category Entity Current Reporting Status us-gaap_DividendsCommonStock Dividend Segments [Axis] Segments [Domain] Other Segments [Member] us-gaap_CapitalizedComputerSoftwareNet Capitalized Computer Software, Net, Ending Balance us-gaap_ImpairmentOfRealEstate Impairment of Real Estate us-gaap_IncreaseDecreaseInReceivables Change in accounts receivable, net Proceeds from the sale of available for sale securities us-gaap_CapitalizedComputerSoftwareAmortization1 Capitalized Computer Software, Amortization Weighted average anti-dilutive options (in shares) Diluted (in shares) Denominator for diluted earnings per share – adjusted weighted average shares outstanding and assumed conversions (in shares) Entity Central Index Key Depreciation and amortization expense Entity Registrant Name Scenario, Forecast [Member] Stock-based compensation related to stock options, restricted shares and employee stock purchase plan Entity [Domain] Legal Entity [Axis] Statement [Table] Scenario [Axis] Statement of Financial Position [Abstract] Scenario, Unspecified [Domain] Diluted (in dollars per share) Denominator for basic earnings per share – weighted average shares outstanding (in shares) Basic (in shares) Diluted earnings per common share and common share equivalents (in dollars per share) Basic (in dollars per share) Basic earnings per common share (in dollars per share) us-gaap_TreasuryStockValue Treasury stock, at cost: 1,988,354 class A shares and 4,962,539 class B shares in 2018 and 934,171 class A shares and 4,625,181 class B shares in 2017 us-gaap_StockRepurchasedDuringPeriodShares Common stock repurchases (in shares) Statement of Cash Flows [Abstract] Entity Common Stock, Shares Outstanding (in shares) Income Statement [Abstract] us-gaap_StockRepurchasedDuringPeriodValue Common stock repurchases us-gaap_IncreaseDecreaseInInventories Change in inventories, net Trading Symbol Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Issuance of common stock under employee stock purchase plan (in shares) Stock options exercised and stock awards (in shares) us-gaap_TableTextBlock Notes Tables (Loss) gain on sale of assets Issuance of common stock under employee stock purchase plan Vesting of restricted share awards (in shares) Stock options exercised and stock awards New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Vesting of restricted share awards Selling, general and administrative expense us-gaap_PaymentsForProceedsFromOtherInvestingActivities Change in other assets Cash flows from financing activities: us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Other long-term liabilities us-gaap_EffectiveIncomeTaxRateReconciliationShareBasedCompensationExcessTaxBenefitAmount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount us-gaap_LiabilitiesAndStockholdersEquity Total liabilities and shareholders’ equity Deferred income taxes, net Retained earnings Interest expense, net us-gaap_StockholdersEquity Total shareholders’ equity Balance Balance Capital lease obligations, net of current maturities Common Class A [Member] us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements Common Class B [Member] Class of Stock [Axis] Class of Stock [Domain] Long-term debt, net of current maturities Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of Stockholders Equity [Table Text Block] Financial Service [Member] us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis Debt Securities, Available-for-sale, Amortized Cost, Total Deferred income tax expense Schedule of Derivative Instruments, Effect on Other Comprehensive Income (Loss) [Table Text Block]