Receivables, Net (Components Of Receivables, Net Of Allowance For Doubtful Accounts) (Details) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Trade receivables	$ 91.0	$ 89.8
Manufacturer receivables	107.3	127.8
Other	34.7	37.5
Trade, manufacturer and other receivables, gross	233.0	255.1
Less: Allowances	(2.7)	(3.7)
Trade, manufacturer and other receivables, net	230.3	251.4
Contracts-in-transit and vehicle receivables	171.8	210.6
Receivables, net	$ 402.1	$ 462.0

The amount due to the company from outside sources, within one year of the balance sheet date, for retail new and used vehicle sales including amounts due from customers and amounts due from financing companies for the financed portion of the vehicle sales price.

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- Definition

The amount due to the company from manufacturers or distributors, within one year of the balance sheet date, including (1) rebates and assistance for holdbacks, floorplan interest and advertising expenses; (2) incentives based on achieving certain objectives; and (3) amounts due for warranty and service work performed for customers.

+ Details

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- Definition

The aggregate amount of trade receivables, manufacturer receivables and other receivables.

+ Details

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- Definition

The aggregate amount of trade receivables, manufacturer receivables and other receivables, reduced to the estimated net realizable fair value by an allowance established of the amount deemed uncertain of collection.

+ Details

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- Definition

The amount due to the company from outside sources, within one year of the balance sheet date, for parts and automotive repair and maintenance services that have been delivered or sold, excluding amounts due from manufacturers. Also includes amounts due from finance organizations, within one year of the balance sheet date, for commissions on the sale of financing products.

+ Details

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- Details

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- Definition

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6965416&loc=d3e5074-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.4)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 8

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.8)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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- Definition

The total amount due to the entity within one year of the balance sheet date (or one operating cycle, if longer) from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such receivables to an amount that approximates their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 4

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 3

-Subparagraph a

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.3,4)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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