Document and Entity Information [Abstract] Statement, Equity Components [Axis] Equity Component [Domain] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Accounts receivable, net Accounts Receivable, Net, Current Inventories, net Inventory, Net Prepaid expenses and other Prepaid Expense and Other Assets, Current Deferred income taxes, net Deferred Tax Assets, Net, Current Deferred income taxes, net Total current assets Assets, Current, Total Total current assets Investments Available-for-sale Securities, Debt Securities, Noncurrent Property and equipment, net Property, Plant and Equipment, Net Goodwill, net Goodwill Other assets, net Other Assets, Noncurrent Other assets, net Total assets Assets, Total Total assets Liabilities and shareholders' equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Floor plan notes payable Notes Payable, Current Current maturities of long-term debt Long-term Debt, Current Maturities Current maturities of capital lease obligations Capital Lease Obligations, Current Trade accounts payable Accounts Payable, Trade, Current Accrued expenses Accrued Liabilities, Current Accrued expenses Total current liabilities Liabilities, Current, Total Total current liabilities Long-term debt, net of current maturities Long-term Debt, Excluding Current Maturities Capital lease obligations, net of current maturities Capital Lease Obligations, Noncurrent Other long-term liabilities Other Liabilities, Noncurrent Deferred income taxes, net Deferred Tax Liabilities, Noncurrent Shareholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock, par value $.01 per share; 1,000,000 shares authorized; 0 shares outstanding in 2011 and 2010 Preferred Stock, Value, Issued Preferred stock, par value Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par value $.01 per share; 60,000,000 class A shares and 20,000,000 class B shares authorized; 27,406,424 class A shares and 10,776,697 class B shares outstanding in 2011; and 26,798,707 class A shares and 10,700,044 class B shares outstanding in 2010 Common Stock, Value, Issued Common stock, par value Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares outstanding Common Stock, Shares, Outstanding Additional paid-in capital Additional Paid in Capital, Common Stock Treasury stock, at cost: 1,639,843 class B shares Treasury Stock, Value Treasury stock, at cost: 1,639,843 class B shares Treasury stock, shares Treasury Stock, Shares Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss, net of tax Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss, net of tax Total shareholders' equity Stockholders' Equity Attributable to Parent, Total Total shareholders' equity Total liabilities and shareholders' equity Liabilities and Equity, Total Total liabilities and shareholders' equity Revenues: Revenues [Abstract] New and used commercial vehicle sales Sales Revenue, Goods, Net Parts and Service Sales Parts and service sales Parts and service sales Lease and rental Operating Leases, Income Statement, Lease Revenue Finance and insurance Financial Services Revenue Other Other Operating Income Other Total revenue Revenues, Total Total revenue Cost of products sold: Cost of Revenue [Abstract] New and used commercial vehicle sales Cost of Goods Sold Parts and Service Sales Cost of Products Sold Parts and service sales Parts and service sales Lease and rental Operating Leases, Rent Expense Lease and rental Total cost of products sold Cost of Revenue, Total Total cost of products sold Gross profit Gross Profit Gross profit Selling, general and administrative Selling, General and Administrative Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Gain (loss) on sale of assets Gain (Loss) on Disposition of Assets Operating income Operating Income (Loss) Operating income Interest income (expense): Interest Income (Expense), Net [Abstract] Interest income Investment Income, Interest Interest expense Interest Expense Interest expense Interest Income (Expense), Net, Total Total interest expense, net Total interest expense, net Income from continuing operations before taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest Income from continuing operations before taxes Provision (benefit) for income taxes Income Tax Expense (Benefit) Provision (benefit) for income taxes Income from continuing operations Income (Loss) from Continuing Operations Attributable to Parent Income from continuing operations Income from discontinued operations, net of tax Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent Income from discontinued operations, net of tax Net income Net Income (Loss) Attributable to Parent Net income Earnings per common share--Basic: Earnings Per Share, Basic [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Basic Share Net income Earnings Per Share, Basic Earnings per common share--Diluted: Earnings Per Share, Diluted [Abstract] Income from continuing operations Income (Loss) from Continuing Operations, Per Diluted Share Net income Earnings Per Share, Diluted Statement [Table] Statement [Line Items] Common Stock Shares Outstanding Class A Common Class A Balance, shares Balance Common Stock Shares Outstanding Class B Common Class B $0.01 Par Value Balance Additional Paid-In Capital Treasury Stock Retained Earnings Accumulated Other Comprehensive Loss Stock options exercised (including tax effect of ($191), $885 and $1,628 for the period ending Dec 31, 2009, 2010 and 2011 respectively), shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Stock options exercised (including tax effect of ($191), $885 and $1,628 for the period ending Dec 31, 2009, 2010 and 2011 respectively) Stock Issued During Period, Value, Stock Options Exercised Stock Issued During Period Value Tax Effect from Share Based Compensation Stock options exercised Stock options exercised Stock-based compensation related to stock options, restricted shares and employee stock purchase plan Adjustments to Additional Paid in Capital, Share-based Compensation, Employee Stock Purchase Program, Requisite Service Period Recognition Vesting of restricted share awards, shares Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Vesting of restricted share awards Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Issuance of common stock under employee stock purchase plan, shares Stock Issued During Period, Shares, Employee Stock Purchase Plans Issuance of common stock under employee stock purchase plan Stock Issued During Period, Value, Employee Stock Purchase Plan Balance, shares Balance Fair value adjustment of interest rate swaps, net of tax Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax Unrealized loss on available-for-sale securities, net of tax Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Adjustments to reconcile net income to net cash used in operating activities, net of acquisitions- Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Gain on sale of property and equipment, net Gain (Loss) on Sale of Property Plant Equipment Gain on sale of property and equipment, net Gain on disposition of equipment centers Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax Gain on disposition of equipment centers Stock-based compensation expense related to employee stock options and employee stock purchases Share-based Compensation Provision (benefit) for deferred income tax expense Deferred Income Tax Expense (Benefit) Excess tax (benefits) provision from stock-based compensation Excess Tax Benefit from Share-based Compensation, Operating Activities Excess tax (benefits) provision from stock-based compensation Change in accounts receivable, net Increase (Decrease) in Accounts Receivable Change in accounts receivable, net Change in inventories Increase (Decrease) in Inventories Change in inventories Change in prepaid expenses and other, net Increase (Decrease) in Prepaid Expense and Other Assets Change in prepaid expenses and other, net Change in trade accounts payable Increase (Decrease) in Accounts Payable, Trade Change in accrued expenses Increase (Decrease) in Accrued Liabilities Change in accrued expenses Net cash (used in) provided by operating activities Net Cash Provided by (Used in) Operating Activities Net cash (used in) provided by operating activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Acquisition of property and equipment Payments to Acquire Property, Plant, and Equipment Acquisition of property and equipment Proceeds from the sale of property and equipment Proceeds from Sale of Property, Plant, and Equipment Business acquisitions Payments to Acquire Businesses, Gross Business acquisitions Proceeds from disposition of equipment centers Proceeds from Divestiture of Businesses Other Payments for (Proceeds from) Other Investing Activities Other Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Net cash used in investing activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Draws (payments) on floor plan notes payable, net Proceeds from (Repayments of) Notes Payable Proceeds from long-term debt Proceeds from Issuance of Long-term Debt Principal payments on long-term debt Repayments of Long-term Debt Principal payments on long-term debt Principal payments on capital lease obligations Repayments of Long-term Capital Lease Obligations Principal payments on capital lease obligations Proceeds from issuance of shares relating to employee stock options and employee stock purchases Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options Excess tax benefits (provision) from stock-based compensation Excess Tax Benefit from Share-based Compensation, Financing Activities Debt issuance costs Payments of Debt Issuance Costs Debt issuance costs Net cash provided by (used in) financing activities Net Cash Provided by (Used in) Financing Activities Net cash provided by (used in) financing activities Net increase in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Net increase in cash and cash equivalents Cash and cash equivalents, beginning of year Cash and cash equivalents, end of year Supplemental disclosure of cash flow information: Supplemental Cash Flow Information [Abstract] Cash Paid During Period for Abstract Cash paid during the year for: Cash paid during the year for: Interest Interest Paid Income taxes, net of refunds Income Taxes Paid, Net Noncash investing and financing activities: Noncash Investing and Financing Items [Abstract] Note Receivable Related to Disposition of Equipment Centers Note receivable related to disposition of equipment centers Note receivable related to disposition of equipment centers Assets acquired under capital leases Fair Value of Assets Acquired ORGANIZATION AND OPERATIONS Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Operations [Abstract] SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Significant Accounting Policies [Abstract] Supplier and Customer Concentration [Text Block] SUPPLIER AND CUSTOMER CONCENTRATION SUPPLIER AND CUSTOMER CONCENTRATION Supplier and Customer Concentration [Abstract] SUPPLIER AND CUSTOMER CONCENTRATION: ACCOUNTS RECEIVABLE Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Accounts Receivable [Abstract] INVENTORIES Inventory Disclosure [Text Block] Inventories [Abstract] VALUATION ACCOUNTS Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] Valuation Accounts [Abstract] FLOOR PLAN NOTES PAYABLE AND LINES OF CREDIT Debt Disclosure [Text Block] Floor Plan Notes Payable and Lines of Credit/ Long-Term Debt [Abstract] LONG-TERM DEBT Long-term Debt [Text Block] FINANCIAL INSTRUMENTS AND FAIR VALUE Fair Value Disclosures [Text Block] Financial Instruments and Fair Value [Abstract] LEASING ACTIVITIES Leases of Lessee Disclosure [Text Block] Leasing Activities [Abstract] SHARE BASED COMPENSATION AND EMPLOYEE BENEFIT PLANS Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Share Based Compensation and Employee Benefit Plans [Abstract] EARNINGS PER SHARE Earnings Per Share [Text Block] Earnings Per Share [Abstract] INCOME TAXES Income Tax Disclosure [Text Block] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Commitments and Contingencies [Abstract] ACQUISITIONS Business Combination Disclosure [Text Block] Acquisitions [Abstract] DISCONTINUED OPERATIONS Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Discontinued Operations [Abstract] MEDIUM-DUTY GMC TRUCK FRANCHISES Asset Impairment Charges [Text Block] Medium-Duty GMC Truck Franchises [Abstract] COMPREHENSIVE INCOME Comprehensive Income (Loss) Note [Text Block] Comprehensive Income [Abstract] UNAUDITED QUARTERLY FINANCIAL DATA Quarterly Financial Information [Text Block] Unaudited Quarterly Financial Data [Abstract] SEGMENTS Segment Reporting Disclosure [Text Block] Segments [Abstract] Amendment Flag Current Fiscal Year End Date Document Period End Date Document Type Entity Central Index Key Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Filer Category Entity Registrant Name Entity Voluntary Filers Entity Well-known Seasoned Issuer Entity Public Float Document Fiscal Period Focus Document Fiscal Year Focus Consolidated Balance Sheets [Abstract] Consolidated Statements of Income [Abstract] Consolidated Statements of Shareholders' Equity [Abstract] Consolidated Statements of Cash Flows [Abstract] Income Taxes [Abstract]