Acquisitions and Dispositions (Details) $ in Millions	3 Months Ended
Mar. 31, 2019 USD ($) franchise dealership	Mar. 31, 2018 USD ($) franchise dealership
Acquisitions and Dispositions (Textual) [Abstract]
Aggregate consideration paid \| $		$ 76.6
Cash received in acquisition \| $		$ 5.1
Net gain on dispositions \| $	$ 5.2
U.S.
Acquisitions and Dispositions (Textual) [Abstract]
Number of dealerships opened	1
Number of franchises awarded	1
Number of dealerships acquired		2
Number of franchises acquired \| franchise		2
Number of dealerships disposed	3
Number of franchises disposed \| franchise	6
U.K.
Acquisitions and Dispositions (Textual) [Abstract]
Number of dealerships opened	1	1
Number of franchises awarded	1	1
Number of dealerships acquired		5
Number of franchises acquired \| franchise		8
Number of dealerships disposed	1
Number of franchises disposed \| franchise	1

Number of dealerships acquired.

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- Definition

Number Of Dealerships Opened

+ References

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Number of franchises acquired.

+ References

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Number Of Franchises Awarded

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Number of franchises disposed.

+ References

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Number of Dealerships Disposed

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

+ References

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Amount of currency on hand as well as demand deposits with banks or financial institutions, acquired at the acquisition date. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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- Definition

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

+ References

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