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Financial Instruments And Fair Value Measurements (Nonfinancial Assets Measured on a Nonrecurring Basis) (Details) $ in Millions | 3 Months Ended |
--- | --- | ---
Mar. 31, 2021 USD ($) | Mar. 31, 2020 USD ($) | Dec. 31, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Gain/(Loss) on goodwill | $ 0.0 | $ (318.3) |
Goodwill impairment | 0.0 | 318.3 |
Franchise rights impairment | 0.0 | 57.5 |
Continuing Operations [Member] | Reported Value Measurement [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets held for sale | 56.3 |  | $ 25.5
Discontinued Operations [Member] | Reported Value Measurement [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Assets held for sale in discontinued operations | 1.1 |  | $ 8.0
Fair Value, Nonrecurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Gain/(Loss) on goodwill | 0.0 | (318.3) |
Gain/(Loss) on franchise rights and other | 0.0 | (59.9) |
Gain/(Loss) on right-of-use assets | (0.1) | (0.4) |
Gain/(Loss) on assets held and used | (0.9) | (5.7) |
Goodwill impairment | 0.0 | 318.3 |
Fair Value, Nonrecurring [Member] | Other Intangible Assets [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Impairment of finite-lived intangibles assets |  | 2.4 |
Fair Value, Nonrecurring [Member] | Franchise Rights [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Franchise rights impairment |  | 57.5 |
Fair Value, Nonrecurring [Member] | Reporting Unit, Premium Luxury [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Gain/(Loss) on goodwill |  | (257.4) |
Goodwill impairment |  | 257.4 |
Fair Value, Nonrecurring [Member] | Reporting Unit, Collision Centers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Gain/(Loss) on goodwill |  | (41.6) |
Goodwill impairment |  | 41.6 |
Fair Value, Nonrecurring [Member] | Reporting Unit, Parts Centers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Gain/(Loss) on goodwill |  | (19.3) |
Goodwill impairment |  | 19.3 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Goodwill | 0.0 | 457.5 |
Franchise rights and other | 0.0 | 26.2 |
Right-of-use assets | 0.0 | 1.4 |
Long-lived assets held and used | $ 6.0 | 1.8 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Franchise rights and other |  | $ 24.6 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Weighted Average Cost of Capital [Member] | Average [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.085 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Minimum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.111 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Maximum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.143 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Discount Rate [Member] | Average [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.121 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Long-term Revenue Growth Rate [Member] | Average [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.020 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Long-term Pretax Income Margin [Member] | Minimum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.006 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Long-term Pretax Income Margin [Member] | Maximum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.028 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Long-term Pretax Income Margin [Member] | Average [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.014 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Contributory Asset Charges [Member] | Minimum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.042 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Contributory Asset Charges [Member] | Maximum [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.121 |
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member] | Franchise Rights [Member] | Valuation Technique, Discounted Cash Flow [Member] | Measurement Input, Contributory Asset Charges [Member] | Average [Member] |  |  |
Fair Value Measurement Inputs and Valuation Techniques [Abstract] |  |  |
Franchise rights, measurement input |  | 0.062 |

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