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Acquisitions and Dispositions (Details) $ in Millions | 3 Months Ended
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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 |

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- Definition Number of franchises acquired. + References No definition available. + Details
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- Definition Number of franchises disposed. + References No definition available. + Details
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- Definition 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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6613-128477 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 30 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=109124213&loc=d3e6578-128477 + Details
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- Definition 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 Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84161108&loc=d3e4845-128472 + Details
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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 Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4582445-111684 + Details
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