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Description of Business and Summary of Significant Accounting Policies (Goodwill and Other Intangible Assets) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Goodwill and Intangible Assets [Line Items] |  |  |
Franchise agreements, minimal contractual terms (in years) | 1 year |  |
Goodwill impairment | $ 0 |  |
Franchise rights impairment | $ 9,600,000 | $ 8,100,000 | $ 0
Minimum [Member] |  |  |
Goodwill and Intangible Assets [Line Items] |  |  |
Other intangibles, useful life | 3 years |  |
Maximum [Member] |  |  |
Goodwill and Intangible Assets [Line Items] |  |  |
Other intangibles, useful life | 30 years |  |
Nonrecurring [Member] | Franchise Rights [Member] |  |  |
Goodwill and Intangible Assets [Line Items] |  |  |
Franchise rights impairment | $ 9,600,000 | $ 8,100,000 | $ 0

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- Definition The minimum contractual term of the Company's various franchise agreements with vehicle manufacturers. + References No definition available. + Details
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