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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

X

- Definition

The minimum contractual term of the Company's various franchise agreements with vehicle manufacturers.

+ References

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Goodwill and Intangible Assets [Line Items]

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Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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-Publisher FASB
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-SubTopic 20
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Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

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-Publisher FASB
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