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Document Fiscal Period Focus Document Period End Date Current Fiscal Year End Date Products and Services [Domain] Net cash used in the exercise, vesting or cancellation of stock incentive awards Products and Services [Axis] Entity Current Reporting Status Entity Voluntary Filers Entity Filer Category Document Type Cost of products sold Selling, General and Administrative Expenses [Member] Cash flows from investing activities: Entity Well-known Seasoned Issuer us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities Total adjustments us-gaap_NetCashProvidedByUsedInOperatingActivities Net cash provided by (used in) operating activities us-gaap_InterestExpenseDebt Interest expense Effect of dilutive stock options (in shares) Other Segments [Member] Segments [Domain] Accounts receivable, less allowance of $149 and $144 Segments [Axis] Accounts receivable, allowance Statement [Table] us-gaap_LineOfCredit Long-term Line of Credit Cash and cash equivalents Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Research and development Letter of Credit [Member] Current assets: us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease Net decrease in cash and cash equivalents Income Statement [Abstract] us-gaap_NetCashProvidedByUsedInFinancingActivities Net cash used in financing activities Credit Facility [Domain] Credit Facility [Axis] Revolving Credit Facility [Member] Deferred income tax assets Cash paid related to tax impact of stock incentive plan transactions us-gaap_StockholdersEquity Total Spartan Motors, Inc. shareholders’ equity us-gaap_PaymentsOfDividends Payment of dividends Selling, general and administrative us-gaap_TableTextBlock Notes Tables Preferred stock, shares issued (in shares) Preferred stock, shares authorized (in shares) Preferred stock, par value (in dollars per share) Inventories Total inventories Other current assets Common stock, shares outstanding (in shares) us-gaap_SharesIssued Balance (in shares) Balance (in shares) Operating expenses: us-gaap_OtherInventoryDemo Other Inventory, Demo, Gross Proceeds from sale of property, plant and equipment Deposits from customers Accrued warranty Non-controlling interest Finished goods Work in process Raw materials and purchased components us-gaap_InventoryValuationReserves Reserve for slow-moving inventory us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest Balance Balance Total shareholders’ equity Dividends declared, per share (in dollars per share) Additional paid in capital us-gaap_PaymentsToAcquirePropertyPlantAndEquipment Purchases of property, plant and equipment Capital expenditures Segment Assets TOTAL ASSETS Shareholders' equity: Current liabilities: Property, plant and equipment, net Entity Registrant Name Goodwill Entity Central Index Key us-gaap_NumberOfReportableSegments Number of Reportable Segments Commitments and Contingencies Disclosure [Text Block] Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenue Other assets Schedule of Loss Contingencies by Contingency [Table Text Block] Entity Common Stock, Shares Outstanding (in shares) Earnings Per Share [Text Block] Segment Reporting Disclosure [Text Block] Scenario [Axis] Scenario, Unspecified [Domain] Intangible assets, net us-gaap_AssetsCurrent Total current assets Supplier [Axis] Share-based Goods and Nonemployee Services Transaction, Supplier [Domain] spar_EqualInstallmentPeriodForPenaltyPertainingToEarlyWarningAndDefectReporting Equal Installment Period for Penalty Pertaining to Early Warning and Defect Reporting The number of years equal installments will be paid pertaining to the penalty for early warning and defect reporting. spar_PenaltyPertainingToEarlyWarningAndDefectReporting Penalty Pertaining to Early Warning and Defect Reporting The fine as per the agreement for issues with the company's early warning and defect reporting procedures. us-gaap_DisclosureTextBlockAbstract Notes to Financial Statements us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic Income (loss) before taxes Income taxes receivable Expense from changes in fair value of contingent consideration us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges Gain on disposal of assets Reclassified from Research and Development Expense to Cost of Products Sold [Member] Represents the reclassification of prior period expenses from research and development expense to cost of products sold. us-gaap_LiabilitiesCurrent Total current liabilities Total restructuring Total restructuring charges included in Statements of Operations. Manufacturing Process Reengineering [Member] Represents manufacturing process re-engineering. Production Relocation Costs [Member] Represents information pertaining to production relocation costs. Inventory Impairment [Member] Represents information pertaining to inventory impairment. Other Specialty Vehicles [Member] Information pertaining to the other specialty vehicles segment. Motorhome Chassis [Member] Information pertaining to the motorhome chassis segment. Aftermarket Parts and Assemblies [Member] Aftermarket parts and assemblies products and services. Payments and adjustments made in period Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Emergency Response Vehicles [Member] Information pertaining to the emergency response vehicles segment. Depreciation and amortization Depreciation and amortization expense Delivery And Service Vehicles [Member] Delivery and service vehicles segment. Specialty Chassis and Vehicles [Member] Information pertaining to the specialty chassis and vehicles segment. Less: net loss attributable to non-controlling interest us-gaap_LiabilitiesAndStockholdersEquity TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY Accrual for severance Anti-dilutive stock awards: Anti-dilutive stock awards [abstract] us-gaap_PaymentsForPreviousAcquisition Payment of contingent consideration on acquisitions Payments for Previous Acquisition Retained earnings Restructuring and Related Activities Disclosure [Text Block] Decrease (increase) in operating assets: Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Subsequent Event Type [Domain] Subsequent Event Type [Axis] Statement of Financial Position [Abstract] Issuance of common stock and the tax impact of stock incentive plan transactions (in shares) us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities Tax expense related to stock incentive plan transactions Stock based compensation related to stock awards Issuance of common stock and the tax impact of stock incentive plan transactions Issuance of restricted stock, net of cancellation (in shares) Other current liabilities and accrued expenses Employee Severance [Member] Issuance of restricted stock, net of cancellation Restructuring and Related Costs [Table Text Block] Type of Restructuring [Domain] Restructuring Type [Axis] Subsequent Event [Member] Statement of Cash Flows [Abstract] Net loss Net income (loss) Statement of Stockholders' Equity [Abstract] Cash flows from operating activities: Cash flows from financing activities: Business Description and Accounting Policies [Text Block] Current portion of long-term debt Diluted net earnings (loss) per share (in dollars per share) us-gaap_DividendsCommonStock Dividends declared ($0.05 per share) Anti-dilutive stock awards (in shares) Diluted weighted average common shares outstanding (in shares) Diluted weighted average common shares outstanding (in shares) us-gaap_IncreaseDecreaseInInventories Inventories Accrued compensation and related taxes Taxes Accounts payable us-gaap_NetCashProvidedByUsedInInvestingActivities Net cash used in investing activities Stock based compensation expense related to restricted stock Basic weighted average common shares outstanding (in shares) Basic weighted average common shares outstanding (in shares) Basic net earnings (loss) per share (in dollars per share) Common stock, $0.01 par value; 40,000 shares authorized; 34,277 and 34,094 outstanding Class of Stock [Axis] Borrowings under credit facilities us-gaap_LettersOfCreditOutstandingAmount Letters of Credit Outstanding, Amount us-gaap_IncreaseDecreaseInIncomeTaxesReceivable Income taxes receivable Accounting Policies [Abstract] Common stock, shares authorized (in shares) Schedule of Weighted Average Number of Shares [Table Text Block] Schedule of Restructuring Reserve by Type of Cost [Table Text Block] Common stock, par value (in dollars per share) us-gaap_IncreaseDecreaseInAccountsReceivable Accounts receivable us-gaap_RepaymentsOfLinesOfCredit Payments on credit facilities us-gaap_EffectiveIncomeTaxRateContinuingOperations Effective Income Tax Rate Reconciliation, Percent Schedule of Inventory, Current [Table Text Block] Preferred stock, no par value: 2,000 shares authorized (none issued) Inventory Disclosure [Text Block] New Accounting Pronouncements, Policy [Policy Text Block] us-gaap_BusinessCombinationContingentConsiderationLiability Business Combination, Contingent Consideration, Liability us-gaap_RestructuringReserve Balance, beginning of period Balance, end of period us-gaap_OperatingExpenses Total operating expenses Statement [Line Items] us-gaap_LitigationSettlementAmount Penalty Charges Litigation Settlement, Amount us-gaap_IncreaseDecreaseInOtherOperatingAssets Other assets Increase (decrease) in operating liabilities: Restructuring charges, cost of products sold Schedule of Product Warranty Liability [Table Text Block] us-gaap_GrossProfit Gross profit Deferred income tax liabilities us-gaap_RepaymentsOfLongTermDebt Payments on long-term debt us-gaap_PriorPeriodReclassificationAdjustment Prior Period Reclassification Adjustment Other non-current liabilities Changes in liability for pre-existing warranties during the period, including expirations spar_IncreaseDecreaseInOtherOperatingLiabilitiesCustomerRebates Accrued customer rebates The net change during the reporting period in accrued customer rebates. GM [Member] Chassis bailment inventory agreement with General Motors Company (GM). Warranties issued during the period us-gaap_ProductWarrantyAccrualPayments Cash settlements made during the period us-gaap_LineOfCreditFacilityCapacityAvailableForTradePurchases Line of Credit Facility, Capacity Available for Trade Purchases us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity Line of Credit Facility, Maximum Borrowing Capacity us-gaap_NonoperatingIncomeExpense Total other income (expense) Equity Component [Domain] Equity Components [Axis] Long-term debt, less current portion us-gaap_IncomeTaxReconciliationStateAndLocalIncomeTaxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount us-gaap_ProductWarrantyAccrualPeriodIncreaseDecrease Accrued warranty Utilimaster [Member] Business acquisition of Utilimaster in November of 2009. Common Stock [Member] Interest and other income Additional Paid-in Capital [Member] General and Administrative us-gaap_PolicyTextBlockAbstract Accounting Policies Accrued customer rebates Aggregate carrying amount of rebates due to customers. Retained Earnings [Member] us-gaap_OperatingIncomeLoss Operating income (loss) Operating income (loss) Other income (expense): Manufacturing process reengineering Restructuring charges us-gaap_IncreaseDecreaseInAccountsPayable Accounts payable us-gaap_IncreaseDecreaseInAccruedSalaries Accrued compensation and related taxes Noncontrolling Interest [Member]