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Goodwill and Intangible Assets, Net (Goodwill) (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Goodwill [Roll Forward] |  |  |  |  |
Goodwill, beginning balance | [1] | $ 1,511.3 |  | $ 1,394.5 |
Acquisitions, dispositions, and other adjustments, net |  | 3.7 | [2] | 116.8 |
Goodwill, ending balance | [1] | 1,515.0 |  | 1,511.3 |
Accumulated impairment losses |  | 1,470.0 |  | 1,470.0 | $ 1,470.0
Reporting Unit, Domestic [Member] |  |  |  |  |
Goodwill [Roll Forward] |  |  |  |  |
Goodwill, beginning balance | [1] | 252.1 |  | 203.1 |
Acquisitions, dispositions, and other adjustments, net |  | (20.4) | [2] | 49.0 |
Goodwill, ending balance | [1] | 231.7 |  | 252.1 |
Accumulated impairment losses |  | 140.0 |  | 140.0 | $ 140.0
Reporting Unit, Import [Member] |  |  |  |  |
Goodwill [Roll Forward] |  |  |  |  |
Goodwill, beginning balance | [1] | 558.2 |  | 570.9 |
Acquisitions, dispositions, and other adjustments, net |  | (25.8) | [2] | (12.7) |
Goodwill, ending balance | [1] | 532.4 |  | 558.2 |
Reporting Unit, Premium Luxury [Member] |  |  |  |  |
Goodwill [Roll Forward] |  |  |  |  |
Goodwill, beginning balance | [1] | 697.4 |  | 620.5 |
Acquisitions, dispositions, and other adjustments, net |  | 14.7 | [2] | 76.9 |
Goodwill, ending balance | [1] | 712.1 |  | 697.4 |
Reporting Unit, Other [Member] |  |  |  |  |
Goodwill [Roll Forward] |  |  |  |  |
Goodwill, beginning balance | [1] | 3.6 |  | 0.0 |
Acquisitions, dispositions, and other adjustments, net |  | 35.2 | [2] | 3.6 |
Goodwill, ending balance | [1] | $ 38.8 |  | $ 3.6 |
[1] | Net of accumulated impairment losses of $1.47 billion associated with our single reporting unit (prior to September 30, 2008, our reporting unit structure was comprised of a single reporting unit) and $140.0 million associated with our Domestic reporting unit, both of which were recorded during the year ended December 31, 2008.
[2] | Includes amounts reclassified to held for sale, which are presented in Other Current Assets in our Consolidated Balance Sheet as of December 31, 2017.

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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
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