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Commitments and Contingencies (Details Textual) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($) dealerships
Manufacturer [Line Items]
Payments for Legal Settlements	$ 1,210
Volkswagen legal claims	$ 14,700
Number of Volkswagen dealers	652
Proceeds from Legal Settlements	$ 0
Volkswagen [Member]
Manufacturer [Line Items]
New vehicle retail unit sales	1.70%
Number Of Dealerships | dealerships	7

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[Line Items] for Manufacturer [Table]

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New vehicle unit sales

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Number of dealerships.

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Number of Volkswagen dealers

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Volkswagen legal claims

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The amount of cash paid for the settlement of litigation or for other legal issues during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

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Cash received for the settlement of litigation during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3536-108585

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