Used Vehicles Used Vehicles [Member] Used Vehicles [Member] Total contracts-in-transit and vehicle receivables Contracts In Transit And Vehicle Receivables, Gross Contracts In Transit And Vehicle Receivables, Gross Hedging Designation [Domain] Hedging Designation [Domain] NET INCOME NET INCOME Net income Net income (loss) Net Income (Loss) Attributable to Parent Entity Emerging Growth Company Entity Emerging Growth Company Operating lease assets Operating Lease, Right-of-Use Asset U.K. Notes U.K. Notes [Member] U.K. Notes [Member] Income Statement Location [Axis] Income Statement Location [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Accounts, Notes, Loans and Financing Receivable by Receivable Type [Axis] Receivable Type [Axis] Entity Address, Address Line One Entity Address, Address Line One Entity Address, Address Line Two Entity Address, Address Line Two Total liabilities Derivative Liability Dividends declared Dividends, Common Stock, Cash Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Additional paid-in capital Additional Paid in Capital, Common Stock Entity Filer Category Entity Filer Category Vehicle receivables Vehicle Receivables, Gross Vehicle Receivables, Gross Other long-term assets Other Assets, Noncurrent Segments [Axis] Segments [Axis] U.S. Notes U.S. Notes [Member] U.S. Notes [Member] Borrowings on other debt Proceeds from Issuance of Other Long-term Debt Net increase in cash and cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Net issuance of treasury shares to stock compensation plans Stock Issued During Period, Value, Employee Stock Purchase Plan, Net Stock Issued During Period, Value, Employee Stock Purchase Plan, Net Borrowings on credit facility — acquisition line Borrowings on Credit Facility Acquisition Line Borrowings on credit facility acquisition line. Stock-based compensation APIC, Share-based Payment Arrangement, Increase for Cost Recognition Used vehicle retail sales Used Vehicles - Retail [Member] Used Vehicles - Retail [Member] Revolving credit facility — floorplan notes payable Floorplan Notes Payable [Member] Floorplan Notes Payable [Member] Dealership Dealership [Member] Dealership Gain on disposition of assets Gain (Loss) on Disposition of Assets Document Fiscal Year Focus Document Fiscal Year Focus Subsequent Event Type [Domain] Subsequent Event Type [Domain] Offset account related to floorplan notes payable - credit facility Floorplan Offset Floorplan offset. Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Long-term debt Total long-term debt Long-term Debt and Lease Obligation Offset account related to floorplan notes payable - manufacturer affiliates FMCC Offset FMCC Offset Floorplan notes payable — manufacturer affiliates (Increase) Decrease Floor Plan Notes The decrease (increase) during the reporting period in the carrying value of revolving financing agreements related to new vehicle inventories with captive finance companies associated with the manufacturer of those vehicles that are due when the vehicles are sold. Tax portion of reclassification out of AOCI Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, Tax Business Combination and Asset Acquisition [Abstract] Number of states in which the entity operates Number of States in which Entity Operates Commitment fee (as a percentage) Line of Credit Facility, Commitment Fee Percentage Business Acquisition [Axis] Business Acquisition [Axis] Business And Organization Business And Organization [Line Items] Business And Organization [Line Items] Cash Flow Hedging Cash Flow Hedging [Member] Line of Credit Facility [Abstract] Line of Credit Facility [Abstract] Reclassification related to de-designated interest rate swaps net of tax benefit of $0.7, $—, $0.7 and $—, respectively Other Comprehensive Income (Loss), Reclassification Of Cash Flow Hedge, Gain (Loss), After Reclassification And Tax Other Comprehensive Income (Loss), Reclassification Of Cash Flow Hedge, Gain (Loss), After Reclassification And Tax Credit Facility [Domain] Credit Facility [Domain] ASSETS Assets: Assets [Abstract] Interest Rate Swaps Interest Rate Swap I [Member] Interest Rate Swaps Forward Starting [Member] New Vehicles New Vehicles [Member] New Vehicles [Member] Change in operating lease assets Operating Lease, Right-Of-Use Asset, Amortization Operating Lease, Right-Of-Use Asset, Amortization Entity Address, City or Town Entity Address, City or Town Retained Earnings Retained Earnings [Member] Debt Instrument [Axis] Debt Instrument [Axis] Prepaid expenses and other assets Increase (Decrease) in Prepaid Expense and Other Assets COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Other interest expense, net Other Interest Expense [Member] Other interest expense. Participating financial institutions (institution) Participating Financial Institution Participating Financial Institution Two Franchises Two Franchises [Member] Two Franchises Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Weighted average interest rate (as a percentage) Debt, Weighted Average Interest Rate COMPREHENSIVE INCOME (LOSS) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Weighted average interest rate (as a percentage) Derivative, Average Fixed Interest Rate Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Entity Interactive Data Current Entity Interactive Data Current Prime Floor Prime Rate [Member] Amount expected to be reclassified from other comprehensive loss into earnings Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Less: allowance for doubtful accounts Contracts In Transit And Vehicle Receivables, Allowance For Doubtful Accounts Contracts In Transit And Vehicle Receivables, Allowance For Doubtful Accounts BASIC EARNINGS PER SHARE (in dollars per share) Basic earnings per common share (in dollars per share) Earnings Per Share, Basic REVENUES Revenue from Contract with Customer [Text Block] Inventories Increase (Decrease) in Retail Related Inventories Document Type Document Type Other comprehensive income (loss) before reclassifications: Other Comprehensive Income (Loss), Before Reclassification [Abstract] Other Comprehensive Income (Loss), Before Reclassification [Abstract] Loss of derivative instruments Derivative, Loss on Derivative Prepaid expenses Prepaid Expense, Current Net pre-tax gain (loss) on dealership dispositions Net Gain (Loss) on Real Estate and Dealership Transactions Net Gain (Loss) on Real Estate and Dealership Transactions Schedule of revenues disaggregated by revenue source and geographical segment Disaggregation of Revenue [Table Text Block] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Unrealized loss on derivative instruments Unrealized Gain (Loss) on Derivatives Entity Current Reporting Status Entity Current Reporting Status Proceeds from employee stock purchase plan Net Issuance Of Common And Treasury Shares To Employee Stock Compensation Plans The aggregate value of common shares issued during the period to fund employee benefit plan. Real estate related Real Estate Related [Member] Real Estate Related [Member] Other Other Noncash Income (Expense) Sub-limit for letters of credit Line Of Credit Facility, Sub-limit Line Of Credit Facility, Sub-limit Other Other Receivable [Member] Other receivable. Aggregate consideration paid for dealerships Business Combination, Consideration Transferred Long-term debt, gross Long-term Debt, Gross Current maturities of long-term debt Long-term Debt and Lease Obligation, Current Borrowings outstanding Long-term debt Long-term Debt CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Document Transition Report Document Transition Report Increase (decrease) in accrual for capital expenditures Increase (Decrease) In Capital Expenditures Accrued Increase (Decrease) In Capital Expenditures Accrued TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity Unrealized gain (loss) on interest rate risk management activities, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Scenario [Axis] Scenario [Axis] Accounts and notes receivable Increase (Decrease) in Accounts and Other Receivables Supplemental Cash Flow Elements [Abstract] Supplemental Cash Flow Elements [Abstract] Carrying value Cash Equivalents, at Carrying Value LIABILITIES AND STOCKHOLDERS’ EQUITY Liabilities and Equity [Abstract] Derivative Derivative [Line Items] Hedging Relationship [Domain] Hedging Relationship [Domain] Interest Rate Swaps Interest Rate Swap [Member] Benefit for income taxes Reclassification from AOCI, Current Period, Tax Accrued expenses and other current liabilities Derivative Liability, Current EARNINGS PER SHARE Earnings Per Share [Text Block] Schedule of cash flow hedges included in accumulated other comprehensive income (loss) Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block] Cash and Cash Equivalents [Domain] Cash and Cash Equivalents [Domain] Contracts-in-transit and vehicle receivables Increase Decrease In Contracts In Transit And Vehicle Receivables The increase (decrease) during the reporting period in the book value of amounts due from financing institutions on retail finance contracts from vehicle sales and dealer incentives due from manufacturers. Also, included are amounts receivable from vehicle wholesale sales. Minimum Minimum [Member] Letters of credit issued on behalf of lessee Letters Of Credit Outstanding As Beneficiary Letters Of Credit Outstanding As Beneficiary INTERIM FINANCIAL INFORMATION Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] GROSS PROFIT Gross Profit Acquisition Line Acquisition line Outstanding balance Long-term Line of Credit Effect of exchange rate changes on cash Effect of Exchange Rate on Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents INCOME BEFORE INCOME TAXES Income (loss) before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Selling, general and administrative expenses Selling, General and Administrative Expense Other current assets Derivative Asset, Current Trading Symbol Trading Symbol Number 0f tranches (tranche) Number Of Tranches Number Of Tranches CURRENT LIABILITIES: Liabilities, Current [Abstract] Receivable Type [Domain] Receivable [Domain] Operating lease liabilities Increase (Decrease) in Operating Lease Liability CASH FLOW INFORMATION Cash Flow, Supplemental Disclosures [Text Block] Restatement [Axis] Revision of Prior Period [Axis] Cash paid for acquisitions, net of cash received Payments to Acquire Businesses, Net of Cash Acquired Accumulated Income (Loss) On Foreign Currency Translation Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Line of credit Line of Credit [Member] Other non-manufacturer facilities Other Non-Manufacturer Affiliate Facilities [Member] Other Non-Manufacturer Affiliate Facilities [Member] Other Comprehensive Income Location [Domain] Other Comprehensive Income Location [Domain] Senior Notes Senior Notes [Member] Floorplan 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. Dividends paid Payments of Ordinary Dividends, Common Stock Accumulated depreciation Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization Derivative Instrument [Axis] Derivative Instrument [Axis] Number of reportable segments Number of Reportable Segments Collision Center Collision Center [Member] Collision Center Rental Vehicles Financed through Credit Facility Rental Vehicle Credit Facility [Member] Rental vehicle credit facility. Outstanding letters of credit Letters of Credit Outstanding, Amount Common stock, $0.01 par value, 50,000,000 shares authorized; 25,357,677 and 25,433,048 shares issued, respectively Common Stock, Value, Issued Disaggregation of Revenue Disaggregation of Revenue [Line Items] Goodwill Goodwill, Acquired During Period Commitments and Contingencies (Note 11) Commitments and Contingencies Accumulated other comprehensive income (loss) Accumulated Other Comprehensive Income (Loss), Net of Tax Diluted: Earnings Per Share, Diluted, Two Class Method [Abstract] Total other debt Other Long-Term Debt And Finance Lease, Liability Other Long-Term Debt And Finance Lease, Liability Debt issuance costs Payments of Debt Issuance Costs Receivables [Abstract] Receivables [Abstract] Real Estate, Type of Property [Axis] Real Estate, Type of Property [Axis] Reclassification of de-designated interest rate swaps net of tax benefit (provision) Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Net issuance of treasury shares to stock compensation plans (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans, Net Stock Issued During Period, Shares, Employee Stock Purchase Plans, Net Document Period End Date Document Period End Date Entity Registrant Name Entity Registrant Name Treasury stock (in shares) Treasury Stock, Shares Total debt Debt, Long-term and Short-term, Combined Amount Tax effect Other Comprehensive Income (Loss) before Reclassifications, Tax Accrued expenses and other current liabilities Accrued Liabilities, Current REVENUES Revenue from contract with customer Revenue from Contract with Customer, Excluding Assessed Tax Business And Organization [Table] Business And Organization [Table] Business And Organization [Table] RECEIVABLES, NET AND CONTRACT ASSETS Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Manufacturer receivables Amounts Due From Manufacturers [Member] Amounts due from manufacturers. Equity [Abstract] Equity [Abstract] Carrying Value Reported Value Measurement [Member] Brazil Note Brazil Note [Member] Brazil Note [Member] Common Stock Common Stock [Member] New vehicle retail sales New Vehicles - Retail [Member] New Vehicles - Retail [Member] Variable Rate [Axis] Variable Rate [Axis] Number of franchises disposed Number Of Franchises Disposed Number of franchises disposed. SEGMENT INFORMATION Segment Reporting Disclosure [Text Block] INCOME FROM OPERATIONS Operating Income (Loss) Current operating lease liabilities Operating Lease, Liability, Current Hedging Designation [Axis] Hedging Designation [Axis] Increase (Decrease) in Stockholders' Equity Increase (Decrease) in AOCI Increase (Decrease) in Stockholders' Equity [Roll Forward] Stock-based compensation Share-based Payment Arrangement, Noncash Expense Variable Rate [Domain] Variable Rate [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Dividends paid (in dollars per share) Common Stock, Dividends, Per Share, Cash Paid Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Treasury Stock Treasury Stock [Member] Asset impairments Asset impairments Asset Impairment Charges Notional value Derivative, Notional Amount Debt, fair value Long-term Debt, Fair Value Other Payments for (Proceeds from) Other Investing Activities Purchases of property and equipment Payments to Acquire Property, Plant, and Equipment Maximum Maximum [Member] Interest rate (as a percentage) Line of Credit Facility, Interest Rate at Period End Intangible franchise rights Indefinite-Lived Franchise Rights CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] TOTAL STOCKHOLDERS’ EQUITY Beginning balance Ending balance Stockholders' Equity Attributable to Parent Floorplan interest expense Floorplan interest expense (pre-tax) Floorplan Interest Expense [Member] Floorplan interest expense. Shares issued (in shares) Common Stock, Shares, Issued Minimum borrowing capacity Line Of Credit Facility, Minimum Borrowing Capacity Line of credit facility minimum borrowing capacity for working capital and general corporate purposes, including acquisitions. Accounts payable and accrued expenses Increase (Decrease) in Accounts Payable and Accrued Liabilities Repayments on credit facility — floorplan line and other Repayments On Credit Facility Floorplan Line The cash outflow resulting from repayments of borrowings under the floorplan line of the revolving credit facility. Borrowings under the floorplan line are used to finance the purchase of specific new, used and rental vehicle inventory. Designated as Hedging Instrument Designated as Hedging Instrument [Member] Repayments of senior notes Repayments of Senior Debt Loss on extinguishment of debt Gain (Loss) on Extinguishment of Debt Repurchases of common stock, amounts based on settlement date Payments for Repurchase of Common Stock STOCKHOLDERS’ EQUITY: Stockholders' Equity Attributable to Parent [Abstract] Changes in the balances of each component of accumulated other comprehensive loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Variable consideration recognized relating to performance obligations satisfied in previous period Contract with Customer, Performance Obligation Satisfied in Previous Period ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Comprehensive Income (Loss) Note [Text Block] Long-term operating lease liabilities Operating Lease, Liability, Noncurrent Other long-term assets Derivative Asset, Noncurrent Interest Expense Interest Expense Debt issued Debt Instrument, Face Amount City Area Code City Area Code Retained earnings Retained Earnings (Accumulated Deficit) Contract with customer, asset, allowance for credit loss Contract with Customer, Asset, Allowance for Credit Loss Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Floorplan Line Revolving Credit Facility, Floorplan Line [Member] Revolving Credit Facility, Floorplan Line [Member] Restatement [Domain] Revision of Prior Period [Domain] Finance leases Finance Lease, Liability Business Acquisition [Line Items] Business Acquisition [Line Items] Income Statement [Abstract] Income Statement [Abstract] Amendment Flag Amendment Flag Other Debt Other Debt [Member] Other Debt Acquisition Line Revolving Credit Facility, Acquisition Line [Member] Revolving Credit Facility, Acquisition Line [Member] Fair Value Estimate of Fair Value Measurement [Member] Proceeds from disposition of franchises, property and equipment Proceeds From Disposition Of Franchise Property And Equipment Cash inflow from the sale of long-lived physical assets, dealership franchises, and related real estate, as applicable. Number of additional forward interest rate swaps Derivative, Number of Instruments Held Contracts-in-transit and vehicle receivables, net Total contracts-in-transit and vehicle receivables, net Contracts In Transit And Vehicle Receivables, Net Amounts due from financing institutions on retail finance contracts from vehicle sales and dealer incentives due from manufacturers. Also, included are amounts receivable from vehicle wholesale sales. Basis of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Other deferred costs, net Other Deferred Costs, Net Provision for income taxes Income Tax Expense (Benefit) Equity Components [Axis] Equity Components [Axis] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Number of franchises acquired Number Of Franchises Acquired Number of franchises acquired. Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] TOTAL CURRENT ASSETS Assets, Current Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Inventories Inventory, Net Reclassification adjustment for loss included in interest expense, net of tax benefit of $0.6, $0.7, $1.3 and $0.9, respectively Amount of income (loss) reclassified from other comprehensive (loss) income into statements of operations Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Schedule of reportable segment information Schedule of Segment Reporting Information, by Segment [Table Text Block] Entity File Number Entity File Number Purchases of treasury stock Stock Repurchased During Period, Value Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Less: Earnings allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Basic Fair Value Measurement Fair Value Measurement, Policy [Policy Text Block] Product and Service [Axis] Product and Service [Axis] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Entity Small Business Entity Small Business FMCC Facility FMCC Facility [Member] FMCC facility. Long-term debt, offset Long-Term Debt, Offset Long-Term Debt, Offset Equity Component [Domain] Equity Component [Domain] Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Other manufacturer affiliate facilities Other Manufacturer Affiliate Facilities [Member] Other Manufacturer Affiliate Facilities [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Statement Statement [Line Items] Unrealized gain (loss) arising during the period, net of tax benefit (provision) of $3.4, $1.5, $(5.1) and $11.2, respectively Amount of unrealized income (loss), net of tax, recognized in other comprehensive (loss) income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Property and equipment, net of accumulated depreciation of $491.1 and $460.2, respectively Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Deferred revenues Increase (Decrease) in Contract with Customer, Liability Liabilities: Liabilities [Abstract] Schedule of carrying value and fair value of the Company’s fixed rate long-term debt Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Demand notes Demand Notes [Member] Demand Notes [Member] Debt Disclosure [Abstract] Debt Disclosure [Abstract] Entity Address, State or Province Entity Address, State or Province Used vehicle wholesale sales Used Vehicles - Wholesale [Member] Used Vehicles - Wholesale [Member] Number of dealerships disposed Number Of Dealerships Disposed Number Of Dealerships Disposed Senior notes Unsecured Long-term Debt, Noncurrent Segment Reporting [Abstract] Segment Reporting [Abstract] Accounts and notes receivable, net Total accounts and notes receivable, net Accounts and Financing Receivable, after Allowance for Credit Loss, Current Borrowings on credit facility — floorplan line and other Borrowings On Credit Facility Floorplan Line The cash inflow resulting from borrowings under the floorplan line of the revolving credit facility. Borrowings under the floorplan line are used to finance the purchase of specific new, used and rental vehicle inventory. Parts and service sales Parts And Service [Member] Parts And Service [Member] Use of Estimates Use of Estimates, Policy [Policy Text Block] Schedule of calculation of EPS Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Entity Shell Company Entity Shell Company Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Local Phone Number Local Phone Number Other comprehensive income (loss), net of taxes Net current period other comprehensive income Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Forecast Forecast [Member] Real estate related and other long-term debt Real estate related debt Other Long-term Debt Basic: Earnings Per Share, Basic, Two Class Method [Abstract] Repayments on credit facility — acquisition line Repayments on Credit Facility Acquisition Line Repayments on credit facility acquisition line. Amount reclassified from accumulated other comprehensive income (loss): Reclassification from AOCI, Current Period [Abstract] Reclassification from AOCI, Current Period [Abstract] TOTAL ASSETS Assets Gain (loss) on legal matters Gain (Loss) Related to Litigation Settlement Restatement Adjustment Revision of Prior Period, Adjustment [Member] Shares authorized (in shares) Common Stock, Shares Authorized Cash paid for interest Interest Paid, Excluding Capitalized Interest, Operating Activities Net income available to diluted common shares Net Income (Loss) Available to Common Stockholders, Diluted Acquisitions and Dispositions Business Combination, Description [Abstract] Net income available to basic common shares Net Income (Loss) Available to Common Stockholders, Basic Interest Rate Swaps Interest Rate Swap II [Member] Interest Rate Swap II Product and Service [Domain] Product and Service [Domain] Schedule of accounts and notes receivable Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Interest rate (as a percentage) Debt Instrument, Interest Rate, Stated Percentage Derivative Contract [Domain] Derivative Contract [Domain] Brazilian Credit Facilities Brazilian Credit Facility [Member] Brazilian Credit Facility [Member] Total new and used vehicle sales New And Used Vehicles [Member] New And Used Vehicles [Member] Schedule of floorplan notes payable Schedule of Line of Credit Facilities [Table Text Block] Revolving Credit Facility Revolving Credit Facility [Member] Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Accounts, Notes, Loans and Financing Receivable Accounts, Notes, Loans and Financing Receivable [Line Items] Real Estate [Domain] Real Estate [Domain] Seven Franchises Seven Franchises [Member] Seven Franchises Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Entity Tax Identification Number Entity Tax Identification Number Brazil Brazil Brazil Segment [Member] Brazil Segment [Member] DILUTED EARNINGS PER SHARE (in dollars per share) Decrease to diluted earnings per common share (in dollars per share) Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Weighted average common shares outstanding (in shares) Weighted average basic common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Segments [Domain] Segments [Domain] Amortization of debt discount and issuance costs Amortization of Debt Issuance Costs and Discounts Hedging Relationship [Axis] Hedging Relationship [Axis] Cash paid for taxes, net of refunds Income Taxes Paid, Net ACQUISITIONS AND DISPOSITIONS Mergers, Acquisitions and Dispositions Disclosures [Text Block] Other interest expense, net (pre-tax) Interest Expense [Member] Number of towns in which the entity operates Number of Towns in which Entity Operates Number of Towns in which Entity Operates Net cash used in financing activities Net Cash Provided by (Used in) Financing Activities Other comprehensive income (loss), net of taxes: Other Comprehensive Income (Loss), Net of Tax [Abstract] Treasury stock, at cost; 7,282,827 and 7,342,546 shares, respectively Treasury Stock, Value Deferred income taxes Deferred Income Tax Liabilities, Net Other long-term liabilities Derivative Liability, Noncurrent Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] U.K. United Kingdom United Kingdom Segment [Member] United Kingdom Segment [Member] Floorplan notes payable — credit facility and other, net Floorplan Notes Payable and Other [Member] Floorplan Notes Payable and Other [Member] FINANCIAL INSTRUMENTS AND FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Accounts payable Accounts Payable, Current Depreciation and amortization expense Depreciation and amortization Depreciation, Depletion and Amortization Number of dealerships Number Of Dealerships Number of dealerships. Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income (loss) AOCI Attributable to Parent [Member] 4.00% Senior Notes 4.00% Senior Notes [Member] 4.00% Senior Notes [Member] Derivative [Table] Derivative [Table] COST OF SALES Cost of Goods and Services Sold Pre-tax OCI, before Reclassifications, before Tax, Attributable to Parent Less: current maturities Long Term Debt And Capital Lease Obligations Excluding Short Term Financing Current Long term debt and capital lease obligations excluding short term financing current. Income Statement Location [Domain] Income Statement Location [Domain] Number of dealerships acquired Number Of Dealerships Acquired Number of dealerships acquired. Lessee rental payment obligations during remaining terms of leases under guarantee agreement Guarantor Obligations, Maximum Exposure Inestimable, Minimum Lease Payments Guaranteed Guarantor Obligations, Maximum Exposure Inestimable, Minimum Lease Payments Guaranteed Less: Earnings allocated to participating securities Undistributed Earnings (Loss) Allocated to Participating Securities, Diluted Accounts and notes receivable Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract] F&I receivables Finance And Insurance Receivables Net [Member] Finance and insurance receivables net. Other long-term liabilities Other Liabilities, Noncurrent Summary of long-term debt Schedule of Long-term Debt Instruments [Table Text Block] Debt Instrument Debt Instrument [Line Items] Earnings Per Share [Abstract] Earnings Per Share [Abstract] Principal payments on other debt Repayments of Other Long-term Debt Total assets Derivative Asset Less: allowance for doubtful accounts Accounts Receivable, Allowance for Credit Loss Document Quarterly Report Document Quarterly Report Severance expense Severance Costs Line of Credit Facility [Table] Line of Credit Facility [Table] Dilutive effect of employee stock purchases, net of assumed repurchase of treasury stock (in shares) Dilutive Effect Of Restricted Stock And Employee Stock Purchases Net Of Assumed Repurchase Of Treasury Stock Dilutive effect of restricted stock and employee stock purchases, net of assumed repurchase of treasury stock. Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Unrealized gain (loss) arising during the period, tax (benefit) provision Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Floorplan notes payable — manufacturer affiliates, net Floorplan Notes Payable, Manufacturer Affiliates [Member] Floorplan Notes Payable, Manufacturer Affiliates [Member] Other Comprehensive Income Location [Axis] Other Comprehensive Income Location [Axis] Share-based Payment Arrangement, Expense Share-based Payment Arrangement, Expense Basic and Diluted Earnings per share Earnings Per Share, Basic and Diluted [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Accounts and notes receivable, net: Accounts Receivable, before Allowance for Credit Loss, Current Total contract assets, net Contract with Customer, Asset, after Allowance for Credit Loss, Current CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of period CASH AND CASH EQUIVALENTS, end of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Schedule of assets and liabilities associated with interest rate derivative instruments Schedule of Derivative Instruments [Table Text Block] BALANCE (in shares) BALANCE (in shares) Shares, Issued Par value (in dollars per share) Common Stock, Par or Stated Value Per Share Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] CURRENT ASSETS: Assets, Current [Abstract] Net unrealized gain (loss) on interest rate risk management activities, net of tax: Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax [Abstract] Entity Central Index Key Entity Central Index Key LIBOR London Interbank Offered Rate (LIBOR) [Member] Security Exchange Name Security Exchange Name Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Pre-tax Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Other interest expense, net Interest Expense, Other Weighted average dilutive common shares outstanding (in shares) Weighted average dilutive common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX Other Comprehensive Income (Loss), Net of Tax Floorplan notes payable — credit facility and other, net of offset account of $326.1 and $160.4, respectively Floorplan Notes Payable Credit Facility Gross Floorplan Notes Payable Credit Facility Gross Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Current Fiscal Year End Date Current Fiscal Year End Date Basis spread on variable rate (as a percentage) Debt Instrument, Basis Spread on Variable Rate Accumulated Income (Loss) On Interest Rate Swaps Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member] Measurement Basis [Axis] Measurement Basis [Axis] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Credit Facility [Axis] Credit Facility [Axis] Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Changes in assets and liabilities, net of acquisitions and dispositions: Increase (Decrease) in Operating Capital [Abstract] CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] TOTAL CURRENT LIABILITIES Liabilities, Current Payments of tax withholding for stock-based awards Payment, Tax Withholding, Share-based Payment Arrangement Contracts-in-transit Contracts In Transit, Gross Contracts In Transit, Gross Other Credit Facilities Other Credit Facilities [Member] Other Credit Facilities [Member] Tax provision of reclassification adjustment Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax Maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity FLOORPLAN NOTES PAYABLE Credit Facilities [Text Block] Credit facilities Floorplan notes payable — manufacturer affiliates, net of offset account of $— and $16.0, respectively 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 Information Segment Reporting Information [Line Items] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Line of Credit Facility Line of Credit Facility [Line Items] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Title of 12(b) Security Title of 12(b) Security Statement [Table] Statement [Table] Other current assets Other Assets, Current Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] DEBT Debt and Capital Leases Disclosures [Text Block] Statistical Measurement [Axis] Statistical Measurement [Axis] Unamortized discount Debt Instrument, Unamortized Discount (Premium), Net Subsequent Event Subsequent Event [Member] Cover [Abstract] Cover [Abstract] Parts and service receivables Parts And Service Receivables [Member] Parts and service receivables. Goodwill Goodwill U.S. United States Segment [Member] United States Segment [Member] UK Credit Facilities UK Credit Facilities [Member] UK Credit Facilities [Member] Scenario [Domain] Scenario [Domain] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Finance, insurance and other, net Financial Service [Member] Cash and Cash Equivalents [Axis] Cash and Cash Equivalents [Axis] Less: unamortized debt issuance costs Debt Instrument, Unamortized Discount Deferred income taxes Deferred Income Tax Expense (Benefit)