Inventories (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Inventories
Retail automotive dealership new vehicles	$ 2,307.9		$ 2,307.9		$ 2,397.0
Retail automotive dealership used vehicles	1,053.8		1,053.8		1,060.8
Retail automotive parts, accessories and other	130.4		130.4		140.8
Retail commercial truck dealership vehicles and parts	258.9		258.9		207.9
Commercial vehicle distribution vehicles, parts and engines	227.0		227.0		233.6
Total inventories	3,978.0		3,978.0		$ 4,040.1
Interest credits and advertising assistance	$ 12.8	$ 13.6	$ 24.9	$ 25.6

Represents the carrying amount of commercial distribution vehicle inventory, net of valuation reserves.

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- Definition

Represents the carrying amount of commercial vehicle inventory, net of valuation reserves.

+ References

No definition available.

+ Details

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- Definition

Carrying amount of new vehicle inventory, net of valuation reserves.

+ References

No definition available.

+ Details

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- Definition

Carrying amount of parts, accessories and other inventory, net of valuation reserves.

+ References

No definition available.

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- Definition

Carrying amount of used vehicle inventory, net of valuation reserves.

+ References

No definition available.

+ Details

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- Definition

Floor plan interest credits and advertising assistance received from vendors, which reduce the cost of sales.

+ References

No definition available.

+ Details

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- Definition

Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6676-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 330
-SubTopic 10
-Section 35
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-URI http://asc.fasb.org/extlink&oid=116846819&loc=d3e3927-108312

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.6(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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