Fair Value Disclosures [Abstract] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Measurements, Fair Value Hierarchy [Domain] Level 1[Member] Fair Value, Inputs, Level 1 [Member] Level 2 [Member] Fair Value, Inputs, Level 2 [Member] Total [Member] Total [Member] Total represents all acqusitions during the period [Member] Fair Value By Asset Class [Axis] Asset Class [Axis] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class Domain Fair Value by Asset Class [Domain] Demand Obligation [Member] Demand Obligation [Member] Demand Obligation [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Recurring [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets: Assets, Fair Value Disclosure [Abstract] Interest Rate Derivative Assets, at Fair Value Interest Rate Derivative Assets, at Fair Value Available-for-sale Securities Available-for-sale Securities, Fair Value Disclosure Assets, Fair Value Disclosure Assets, Fair Value Disclosure Liabilities: Liabilities, Fair Value Disclosure [Abstract] Interest rate derivative financial instruments Interest Rate Derivative Liabilities, at Fair Value Liabilities, Fair Value Disclosure Liabilities, Fair Value Disclosure Interim Accounting Policies [Abstract] Interim Accounting Policies [Abstract] Basis of Presentation [Text Block] Basis of Presentation and Significant Accounting Policies [Text Block] Segment Reporting Disclosure [Text Block] Segment Reporting, Policy [Policy Text Block] Consolidation, Variable Interest Entity, Policy [Policy Text Block] Consolidation, Variable Interest Entity, Policy [Policy Text Block] Recent Accounting Pronouncements Policy [Text Block] Recent Accounting Pronouncements Policy [Text Block] Recent accounting pronouncements. Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Segments [Axis] Business Segments [Axis] Segment [Domain] Segment [Domain] U.S. [Member] U.S. [Member] U.S. represents the companies reportable segment of operating companies in The U.S. [Member] U.K. [Member] U.K. [Member] U.K. represents the companies reportable segment of operating companies in The U.K. [Member] Brazil [Member] Brazil [Member] Brazil represents the companies reportable segment of operating companies in Brazil [Member] Countries And States [Axis] Countries And States [Axis] Countries And States [Axis] Countries And States [Domain] Countries And States [Domain] Countries And States [Domain] BRAZIL BRAZIL UNITED KINGDOM UNITED KINGDOM TEXAS TEXAS GEORGIA GEORGIA UNITED STATES UNITED STATES Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Collision Centers [Member] Collision Centers [Member] Collision Centers [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Assets, Current Assets, Current Business Acquisition, Purchase Price Allocation, Goodwill Amount Business Acquisition, Purchase Price Allocation, Goodwill Amount Acquisitions and Dispositions (Textual) [Abstract] Acquisitions and Dispositions (Textual) [Abstract] Acquisitions and dispositions. Number of dealerships acquired Number Of Dealerships Acquired Number of dealerships acquired. Number of franchises acquired Number of Franchises Acquired Number of franchises acquired. Acquisition Costs, Cumulative Acquisition Costs, Cumulative Business Acquisition, Cost of Acquired Entity, Purchase Price Business Acquisition, Cost of Acquired Entity, Purchase Price Business Combination, Consideration Transferred Business Combination, Consideration Transferred Debt assumed as part of consideration paid Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt Other Expenses Other Expenses Cash paid in acquisitions, net of cash received Payments to Acquire Businesses, Net of Cash Acquired Number of dealerships disposed Number of Dealerships Disposed Number of dealerships disposed. Number of Franchises Disposed Number of Franchises Disposed Number of franchises disposed. Gain (Loss) on Sale of Business Gain (Loss) on Sale of Business Inventories, net Inventory, Net Property, Plant and Equipment, Net Property, Plant and Equipment, Net Intangible Assets, Net (Including Goodwill) Intangible Assets, Net (Including Goodwill) Other Assets Other Assets Total assets Assets Liabilities, Current Liabilities, Current Deferred Tax Liabilities, Net Deferred Tax Liabilities, Net Long-term Debt Long-term Debt Liabilities Liabilities Organization, Consolidation and Presentation of Financial Statements [Abstract] Business and Organization [Table] Business And Organization [Table] Business And Organization [Table] Variable Interest Entities [Axis] Variable Interest Entities [Axis] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Classification [Domain] Variable Interest Entity, Primary Beneficiary [Member] Variable Interest Entity, Primary Beneficiary [Member] Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Segment, Geographical [Domain] East [Member] East [Member] East [Member] West [Member] West [Member] West [Member] Business and Organization [Line Items] Business And Organization [Line Items] Business And Organization [Line Items] Number of States in which Entity Operates Number of States in which Entity Operates Number of Towns in which Entity Operates Number of Towns in which Entity Operates Number of Towns in which Entity Operates Number of dealerships Number Of Dealerships Number of dealerships. Long-Lived Assets Long-Lived Assets Liabilities, Noncurrent Liabilities, Noncurrent Earnings Per Share [Abstract] Basic and Diluted Earnings per share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Balance Sheet Accounts [Abstract] Balance Sheet Accounts [Abstract] Inventories [Table] Inventories [Table] Inventories. Inventories [Axis] Inventories [Axis] Inventories [Axis] Inventories [Domain] Inventories [Domain] Inventories [Domain] New vehicles [Member] New Vehicles [Member] New vehicles. Used vehicles [Member] Used Vehicles [Member] Used vehicles. Rental vehicles [Member] Rental Vehicles [Member] Rental vehicles. Parts, accessories and other [Member] Parts Accessories And Other [Member] Parts accessories and other. Inventories [Line Items] Inventories [Line Items] Inventories. Summary of inventories Inventory, Net [Abstract] Lower of cost or market reserves Inventory Valuation Reserves Inventories, net Inventory, Gross Inventory, Gross Debt Disclosure [Abstract] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Convertible Senior Notes Due Two Zero Three Six [Member] Convertible Senior Notes Due Two Zero Three Six [Member] Convertible senior notes due 2036. Convertible Senior Notes Due Two Zero Two Zero [Member] Convertible Senior Notes Due Two Zero Two Zero [Member] Convertible senior notes due 2020. Debt Instrument [Line Items] Debt Instrument [Line Items] Summary of long-term debt Schedule of Long-term Debt Instruments [Table Text Block] Contractual interest expense and the discount amortization Contractual Interest Expense And Discount Amortization [Table Text Block] Contractual interest expense and discount amortization. Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Common Stock Common Stock [Member] Additional Paid-in-Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) [Member] Treasury Stock Treasury Stock [Member] Statement [Line Items] Statement [Line Items] Beginning balance Stockholders' Equity Attributable to Parent Beginning balance, shares Shares, Issued Net income Net Income (Loss) Attributable to Parent Other comprehensive income (loss), net Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Stock Issued During Period, Value, Treasury Stock Reissued Stock Issued During Period, Value, Treasury Stock Reissued Equity component of 3.00% Convertible Note issuance, net of deferred tax liability Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt Issuance of common and treasury shares to employee benefit plans, shares Issuance of Common and Treasury Shares to Employee Benefit Plans Shares The number of common shares issued during the period to fund employee benefit plan. Issuance of common and treasury shares to employee benefit plans Issuance of Common and Treasury Shares to Employee Benefit Plans The aggregate value of common shares issued during the period to fund employee benefit plan. Tax effect from options exercised and the vesting of restricted shares Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Stock-based compensation Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Cash dividends Dividends, Common Stock, Cash Ending balance Ending balance, shares Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Accumulated Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Statement of Cash Flows [Abstract] Convertible senior notes stated rate Debt Instrument, Interest Rate, Stated Percentage Business Combinations - Pro forma information [Abstract] Business Combinations - Pro forma information [Abstract] Business Acquisition, Pro Forma Revenue Business Acquisition, Pro Forma Revenue Business Acquisition, Pro Forma Net Income (Loss) Business Acquisition, Pro Forma Net Income (Loss) Commitments and Contingencies Disclosure [Abstract] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Schedule of Carrying Amounts and Classification of Assets and Liabilities of VIE[Table Text Block] Schedule of Variable Interest Entities [Table Text Block] 2.25% Purchased Options [Member] Purchased Call Option [Member] 2.25% Warrants [Member] Two Point Two Five Percent Warrants [Member] 2.25% Warrants. 3.00% Notes [Member] Three Point Zero Zero Percent Notes [Member] 3.00% Notes. 3.00% Warrants [Member] Warrant [Member] 3.00% Purchased Options [Member] Three Point Zero Zero Percent Purchased Options [Member] 3.00% Purchased options. Debt Instrument [Line Items] Earnings Per Share (Textual) [Abstract] Earnings Per Share (Textual) [Abstract] Earnings per share. Debt interest rate Dividend Threshold for Adjustment to Conversion Price Dividend Threshold for Adjustment to Conversion Price Dividend threshold for adjustment to conversion price. Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instruments, Gain (Loss) by Hedging Relationship, by Income Statement Location, by Derivative Instrument Risk [Table] Derivative Instrument Risk [Axis] Derivative Instrument Risk [Axis] Derivative Contract Type [Domain] Derivative Contract Type [Domain] Interest Rate Swap Contracts [Member] Interest Rate Swap [Member] Derivative Instruments, Gain (Loss) by Income Statement Location [Axis] Income Statement Location [Axis] Income Statement and Other Comprehensive Income (Loss) Location [Domain] Income Statement Location [Domain] Floorplan Interest Expense [Member] Floorplan Interest Expense [Member] Floorplan interest expense. Other Interest Expense [Member] Other Interest Expense [Member] Other interest expense. Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Floor Plan Interest Expense Floor Plan Interest Expense Interest expense incurred on borrowings under the floorplan line of the credit facility and arrangements with vehicle manufacturer affiliates for the financing of specific new, used and rental vehicle inventory. Interest expense also includes the net impact of interest rate swap settlements during the period, which are designed to hedge exposure to variable interest rates. Derivatives in cash flow hedging relationship Derivatives in Cash Flow Hedging Relationship [Abstract] Derivatives in cash flow hedging relationship. Interest rate swap contracts Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Location of Loss Reclassified from OCI into Statements of Operations Location of Loss Reclassified from Other Comprehensive Income into Statements of Operations [Abstract] Location of loss reclassified from other comprehensive income into statements of operations. Interest Expense Interest Expense EARNINGS PER SHARE Earnings Per Share [Text Block] Equity [Abstract] ACCUMULATED OTHER COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Credit Facilities [Abstract] Credit facilities. Line of Credit Facility [Table] Line of Credit Facility [Table] Line of Credit Facility [Axis] Lender Name [Axis] Line of Credit Facility, Lender [Domain] Line of Credit Facility, Lender [Domain] New Vehicle [Member] New Vehicle [Member] New Vehicle [Member] Used Vehicle [Member] Used Vehicle [Member] Used Vehicle [Member] Rental Vehicle [Member] Rental Vehicle Credit Facility [Member] Rental vehicle credit facility. FMCC Facility [Member] Fmcc Facility [Member] FMCC facility. Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Outstanding balances under financing arrangements Line of Credit Facility [Abstract] Floorplan Offset Floorplan Offset Floorplan offset. Floorplan notes payable - manufacturer affiliates Floorplan Notes Payable Manufacturer Affiliates Amounts payable for the financing of specific new vehicle inventory with Ford Motor Credit Company, the financing of new and used vehicle inventory in the United Kingdom with BMW Financial Services and the financing of rental vehicle inventory with several other manufacturers. Payments on floor plan notes payable are generally due as the vehicles are sold. Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill, Subsequent Recognition of Deferred Tax Asset Goodwill, Subsequent Recognition of Deferred Tax Asset Roll-forward of intangible franchise rights and goodwill accounts Roll Forward of Intangible Franchise Rights and Goodwill Accounts [Abstract] Roll-forward of intangible franchise rights and goodwill accounts. Intangible Franchise Rights Indefinite-lived Intangible Assets [Roll Forward] Beginning Balance Indefinite-Lived Intangible Assets (Excluding Goodwill) Additions through acquisitions Indefinite-lived Intangible Assets, Acquired During Period Disposition of Intangible Franchise Rights Indefinite-lived Intangible Assets, Written off Related to Sale of Business Unit Impairment of Intangible Assets, Finite-lived Impairment of Intangible Assets, Finite-lived Currency Translation Indefinite-lived Intangible Assets, Translation and Purchase Accounting Adjustments Ending Balance Goodwill Goodwill [Roll Forward] Beginning Balance Goodwill Additions through acquisitions Goodwill, Acquired During Period Dispositions of Goodwill Goodwill, Written off Related to Sale of Business Unit Currency translation Goodwill, Translation Adjustments Ending Balance Accumulated Impairments Accumulated Impairments Accumulated impairments.