AAA Credit Rating A A A Credit Rating [Member] AAA credit rating Accounts Notes And Loans Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts Notes And Loans Receivable Net Current Trade accounts and notes receivable, net of allowance for doubtful accounts of ¥ 7,904 million in 2011 and ¥ 7,293 million in 2012 (notes 3, 9 and 20) Accounts Notes Loans And Financing Receivable By Receivable Type [Axis] Accounts, Notes, Loans and Financing Receivable by Receivable Type [Axis] Accounts Payable Current Accounts Accounts Payable Current [Abstract] Trade payables: Accounts Payable Related Parties Current And Noncurrent Amounts due to Accounts Receivable Related Parties Amounts due from Accrued Income Taxes Current Income taxes payable (note 11) Accrued Liabilities Current Accrued expenses (note 13) Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Less accumulated depreciation and amortization Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax Balance at end of year Balance at beginning of year Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Net Of Tax Balance at end of year Balance at beginning of year Amounts recognized in accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Postretirement Plans Net Of Tax Balance at end of year Balance at beginning of year Accumulated Other Comprehensive Income Loss Foreign Currency Translation Adjustment Net Of Tax Balance at end of year Balance at beginning of year Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income Loss [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income Loss Net Of Tax Balance at end of year Balance at beginning of year Accumulated other comprehensive income (loss), net (notes 7, 11, 13, 15 and 17) Accumulated Other Comprehensive Income Loss Net Of Tax [Abstract] Total accumulated other comprehensive income (loss): Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income Loss [Table] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income [Member] Accumulated other comprehensive income (loss), net Additional Information About Entitys Reportable Segments Functions Additional Paid In Capital Capital surplus Additional Paid In Capital [Member] Capital surplus Additions To Noncurrent Assets Capital expenditures Cumulative effect of initial adoption of new accounting principle on stockholders' equity, net of tax. This element can be used, generally, for the adjustment relating to a new accounting principle. Adjustment For Cumulative Effect Of Initial Adoption Of New Accounting Principle Adjustment resulting from the adoption of new accounting standards on variable interest entities Adjustment In Retained Earnings Adjustment In Retained Earnings Adjustment in retained earnings Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: The amount of current loan receivable as of balance sheet date. Advances Current Advances The amount of non current loan receivable as of balance sheet date. Advances Non Current Advances Advertising and Sales Promotion Costs and Product Warranty Expense, Policy Advertising And Sales Promotion Costs And Product Warranty Expense Policy [Text Block] Product-Related Expenses Advertising Expense Advertising and sales promotion costs Affiliated Companies and Other Equity Method Investees Affiliated Companies And Other Equity Method Investees [Text Block] Significant Investments in Affiliates Accounted for Under Equity Method Allowance for Credit Losses Allowance For Credit Losses Ending Balance Beginning Balance Allowance for Credit Losses Allowance For Credit Losses [Member] Finance subsidiaries-receivables: Allowance for credit losses Allowance For Credit Losses On Financing Receivables Table [Text Block] Allowance for Credit Losses on Finance Receivables Allowance For Doubtful Accounts [Member] Trade accounts and notes receivable: Allowance for doubtful accounts Allowance For Doubtful Accounts Receivable Current Trade accounts and notes receivable, allowance for doubtful accounts Allowance For Doubtful Accounts Receivable Noncurrent Other assets, allowance for doubtful accounts Allowance for Losses on Lease Residual Values Allowance For Losses On Lease Residual Values Allowance for losses on lease residual values Allowance for Losses on Lease Residual Values Allowance For Losses On Lease Residual Values [Member] Finance subsidiaries-receivables: Allowances for losses on lease residual values All Terrain Vehicles and Relevant Parts All Terrain Vehicles And Relevant Parts [Member] All Terrain Vehicles and Relevant Parts Amended and Restated Date Amended And Restated Date Amendments to law, approved date Amendment Flag Amendment Flag Arrangements And Nonarrangement Transactions [Member] Arrangements and Non-arrangement Transactions [Domain] Asset Backed Notes Maturing Through 2013 Asset Backed Notes Maturing Through 2013 [Member] Asset Backed Notes Maturing Through 2013 Asset Backed Notes Maturing Through 2015 Asset Backed Notes Maturing Through 2015 [Member] Asset Backed Notes Maturing Through 2015 Asset Backed Securities [Member] Asset backed securities Asset Impairment Charges Damaged and impairment losses on long-lived assets Asset Retirement Obligations Policy Asset Retirement Liability Assets Assets Total assets Assets [Abstract] Assets Assets Current Total current assets Assets Current [Abstract] Current assets: Assets Fair Value Disclosure Total Auction Rate Securities [Member] Auction rate securities Automobile Business Automobile Business [Member] Automobile business Automobiles and Relevant Parts Automobiles And Relevant Parts [Member] Automobiles and relevant parts Available For Sale Securities Fair value Available For Sale Securities [Abstract] Available-for-sale Available For Sale Securities Amortized Cost Cost Availableforsale Securities Continuous Unrealized Loss Position 12 Months Or Longer Aggregate Losses 1 12 months or longer Availableforsale Securities Continuous Unrealized Loss Position Aggregate Losses 1 Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total Available For Sale Securities Continuous Unrealized Loss Position Aggregate Losses [Abstract] Available-for-sale Available For Sale Securities Continuous Unrealized Loss Position Fair Value Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value, Total Available For Sale Securities Continuous Unrealized Loss Position Fair Value [Abstract] Available-for-sale Availableforsale Securities Continuous Unrealized Loss Position Less Than 12 Months Aggregate Losses 1 Less than 12 months Available For Sale Securities Continuous Unrealized Loss Position Less Than Twelve Months Fair Value Less than 12 months Available For Sale Securities Continuous Unrealized Loss Position Twelve Months Or Longer Fair Value 12 months or longer Available For Sale Securities Fair Value Disclosure Available-for-sale securities Availableforsale Securities Gross Unrealized Gain Gross unrealized gains Available For Sale Securities Gross Unrealized Losses 1 Gross unrealized losses Balance Sheet Location [Domain] Balance Sheet Location [Domain] Bank Loans Short-term bank loans Bank Loans Maturing Through 2029 Bank Loans Maturing Through 2029 [Member] Bank Loans Maturing Through 2029 Bank Loans Maturing Through 2031 Bank Loans Maturing Through 2031 [Member] Bank Loans Maturing Through 2031 Basis of Presentation Basis Of Presentation Policy [Text Block] Basis of Presenting Consolidated Financial Statements Benefit Costs Benefit Costs [Member] Benefit Costs Benefit Obligation [Member] Benefit Obligation [Member] Benefit Obligation Building [Member] Building Buildings And Improvements Gross Buildings Business Acquisition Acquiree [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Business Acquisition Business Acquisition Cost Of Acquired Entity Liabilities Incurred Consideration to be paid in installments Capital Additions [Member] Capital additions This element represents movements related to capital transactions between a parent company and consolidated subsidiaries or affiliated companies and other transactions which are not defined in the taxonomy. Capital Transactions And Others Capital transactions and others Carrying Reported Amount Fair Value Disclosure [Member] Carrying amount Cash And Cash Equivalents At Carrying Value Cash and cash equivalents at end of year Cash and cash equivalents at beginning of year Cash and cash equivalents Cash And Cash Equivalents [Member] Cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Net change in cash and cash equivalents Cash And Cash Equivalents Policy [Text Block] Cash Equivalents Cash, cash equivalents and marketable securities. Cash Cash Equivalents And Marketable Securities Unallocated corporate assets consist primarily of cash and cash equivalents and marketable securities Cash Flow Supplemental Disclosures [Text Block] Supplemental Disclosures of Cash Flow Information Catastrophic Event [Domain] Catastrophic Event [Domain] Certificates Of Deposit At Carrying Value Certificates of deposit 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] Classification Of Variable Interest Entity [Domain] Variable Interest Entity, Classification [Domain] Amount collected in lease/loan receivables held by our subsidiaries, which carry out financial business such as leasing/loans. Collection Of Finance Subsidiaries Receivables Collections of finance subsidiaries-receivables (note 1(w)) Commercial Loan [Member] Commercial loans Commercial Paper Commercial paper Commercial Paper [Member] Commercial Paper Commingled and Other Mutual Funds Commingled And Other Mutual Funds [Member] Commingled and Other Mutual Funds Commitments And Contingencies Commitments and contingent liabilities (notes 18 and 19) Commitments and Contingencies Disclosure [Line Items] Commitments And Contingencies Disclosure [Line Items] Commitments and Contingencies Disclosure [Line Items] Commitments and Contingencies Disclosure [Table] Commitments And Contingencies Disclosure [Table] Commitments and Contingencies Disclosure [Table] Commitments And Contingencies Disclosure [Text Block] Commitments and Contingent Liabilities Common Stock Dividends Per Share Cash Paid Dividends per share Common Stock [Member] Common stock Common Stock Shares Authorized Common stock, authorized Common Stock Shares Issued Common stock, issued Common Stock Value Common stock, authorized 7,086,000,000 shares; issued 1,811,428,430 shares Component Of Operating Other Cost And Expense [Line Items] Component of Operating Other Cost and Expense [Line Items] Component Of Other Operating Cost And Expense [Table] Component of Other Operating Cost and Expense [Table] Components of Deferred Tax Assets and Liabilities Components Of Deferred Tax Assets And Liabilities Table [Text Block] Temporary Differences that Give Rise to Significant Portions of Deferred Tax Assets and Deferred Tax Liabilities Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Total comprehensive income (loss) Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest [Abstract] Comprehensive income (loss): Comprehensive Income Note [Text Block] Accumulated Other Comprehensive Income (Loss) Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) and Reclassification Adjustments. Comprehensive Income Tax Expenses Benefits Table [Text Block] Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) and Reclassification Adjustments Consolidation Policy [Text Block] Consolidation Policy Construction In Progress Gross Construction in progress Consumer Portfolio Segment [Member] Consumer Portfolio Segment Corporate Debt Securities [Member] Corporate bonds Corporate Elimination [Member] Corporate Elimination Cost Of Revenue Cost of sales Cost of sales (notes 1(u), 1(v) and 2) Costs And Expenses Cost of sales, SG&A and R&D expenses Cost of sales, SG&A and R&D expenses Costs And Expenses [Abstract] Operating costs and expenses: Currency Swap [Member] Currency swap agreements Current Fiscal Year End Date Current Fiscal Year End Date Current Income Tax Expense Benefit Current Dealer Loans Dealer Loans [Member] Dealer loans Dealer wholesale flooring Dealer Wholesale Flooring [Member] Wholesale flooring Debt Disclosure [Line Items] Debt Disclosure [Line Items] Debt Disclosure [Line Items] Debt Disclosure [Table] Debt Disclosure [Table] Debt Disclosure [Table] Debt Disclosure [Text Block] Short-term and Long-term Debt Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument Interest Rate Stated Percentage Interest rate Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument Name [Domain] Debt Instrument, Name [Domain] Debt Instrument [Table] Schedule of Long-term Debt Instruments [Table] Debt Instrument Unamortized Discount Less unamortized discount, net Debt Outstanding Debt Outstanding Debt Debt Securities [Member] Debt Securities Deferred Income Tax Expense Benefit Deferred Deferred income taxes Deferred Tax Assets Gross Total gross deferred tax assets Deferred Tax Assets Inventory Inventories Deferred Tax Assets Liabilities Net Net deferred tax asset (liability) Deferred Tax Assets Net Net deferred tax assets Deferred Tax Assets Net [Abstract] Deferred tax assets: Deferred Tax Assets Net Current Current assets-Deferred income taxes Deferred income taxes (note 11) Decrease in deferred tax assets attributable to the impact on changes in Japanese tax laws at the enactment date of the laws. Deferred Tax Assets Net Increase Decrease Deferred tax assets decreased Deferred Tax Assets Net Noncurrent Other assets Deferred Tax Assets Operating Loss Carryforwards Operating loss carryforwards Deferred Tax Assets Other Other Deferred Tax Assets, Property Plant And Equipment Deferred Tax Assets Property Plant And Equipment Property, plant and equipment Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Bonuses Accrued bonus Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions Pension and other postretirement benefits Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts Allowance for dealers and customers Deferred Tax Assets Valuation Allowance Less valuation allowance Deferred Tax Liabilities Total gross deferred tax liabilities Deferred Tax Liabilities [Abstract] Deferred tax liabilities: Deferred Tax Liabilities Current Other current liabilities Deferred Tax Liabilities Deferred Expense Capitalized Inventory Costs Inventories Deferred Tax Liabilities, Direct Financing Lease Transactions Deferred Tax Liabilities Direct Financing Lease Transactions Direct financing lease transactions Deferred Tax Liabilities Noncurrent Deferred income taxes Other liabilities Deferred Tax Liabilities, Operating Lease Transactions Deferred Tax Liabilities Operating Lease Transactions Operating lease transactions Deferred Tax Liabilities Other Other Deferred Tax Liabilities Prepaid Pension Costs Prepaid pension expenses Deferred Tax Liabilities, Property, Plant and Equipment, Excluding Lease Transactions Deferred Tax Liabilities Property Plant And Equipment Excluding Lease Transactions Property, plant and equipment, excluding lease transactions Deferred Tax Liabilities Undistributed Foreign Earnings Undistributed earnings of subsidiaries and affiliates Deferred Tax Liabilities, Unrealized Gains on Marketable Securities Deferred Tax Liabilities Unrealized Gains On Marketable Securities Net unrealized gains on available-for-sale securities Deferred Tax Liability Not Recognized Amount Of Unrecognized Deferred Tax Liability Deferred tax liabilities not recognized on indefinitely reinvested foreign earnings Defined Benefit Plan Accumulated Benefit Obligation Accumulated benefit obligations Defined Benefit Plan Accumulated Other Comprehensive Income Before Tax Total Defined Benefit Plan Accumulated Other Comprehensive Income Before Tax [Abstract] Amounts recognized in accumulated other comprehensive income (loss) consist of: Defined Benefit Plan Accumulated Other Comprehensive Income Net Gains Losses Before Tax Actuarial loss (gain) Defined Benefit Plan Accumulated Other Comprehensive Income Net Prior Service Cost Credit Before Tax Prior service cost (benefit) Defined Benefit Plan Accumulated Other Comprehensive Income Net Transition Assets Obligations Before Tax Net transition obligation Defined Benefit Plan Actual Return On Plan Assets Actual return on plan assets Defined Benefit Plan Actual Return On Plan Assets [Abstract] Actual return on plan assets: Defined Benefit Plan Actual Return On Plan Assets Sold During Period Relating to assets sold during the period Defined Benefit Plan Actual Return On Plan Assets Still Held Relating to assets still held at the reporting date Defined Benefit Plan Actuarial Net Gains Losses Actuarial gain (loss) Defined Benefit Plan Amortization Of Gains Losses Amortization of actuarial loss (gain) Defined Benefit Plan Amortization Of Net Gains Losses Estimated actuarial loss for defined pension plans that will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost over the next fiscal year Defined Benefit Plan Amortization Of Net Prior Service Cost Credit Estimated prior service cost (benefit) for defined pension plans that will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost over the next fiscal year Defined Benefit Plan Amortization Of Net Transition Asset Obligation Estimated net transition obligation for defined pension plans that will be amortized from accumulated other comprehensive income (loss) into net periodic benefit cost over the next fiscal year Defined Benefit Plan Amortization Of Prior Service Cost Credit Amortization of prior service cost (benefit) Defined Benefit Plan Amortization Of Transition Obligations Assets Amortization of net transition obligation Defined Benefit Plan Amounts Recognized In Balance Sheet Total Defined Benefit Plan Amounts Recognized In Balance Sheet [Abstract] Amounts recognized in the consolidated balance sheets consist of: Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Discount rate Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Rate Of Compensation Increase Rate of salary increase Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Discount rate Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets Expected long-term rate of return Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Rate Of Compensation Increase Rate of salary increase Defined Benefit Plan Benefit Obligation Benefit obligations at end of year Benefit obligations at beginning of year