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Commitments and Contingencies - Additional Information (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract] |  |
Lease exit costs accrual | $ 10,777,000 | $ 6,478,000
Other Commitments [Line Items] |  |
Maximum exposure associated with general indemnifications | $ 5,000,000 | $ 6,000,000
General indemnifications minimum expiration period | 1 year |
General indemnifications maximum expiration period | 3 years |
Percentage of dealership that is accounted for under the equity method | 50.00% | 50.00%
Contingent liability reserve balance after reduction | $ 2,800,000 | $ 2,800,000
Acquired business, earnings targets, maximum term | 10 years |
Maximum aggregate earnout payment | $ 80,000,000 |
Other accrued liabilities |  |
Other Commitments [Line Items] |  |
Amount reserved for pending proceedings | 4,500,000 | 3,000,000
Other long-term liabilities |  |
Other Commitments [Line Items] |  |
Amount reserved for pending proceedings | $ 200,000 | $ 200,000

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- Definition Undiscounted amount of the accrual for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q1) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 + Details
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- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
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