Schedule of Other Current Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Disclosure Schedule Of Other Current Assets [Abstract]
Prepaid expenses	$ 192us-gaap_PrepaidExpenseCurrent	$ 187us-gaap_PrepaidExpenseCurrent
Sales and use tax	125car_SalesAndUseTaxes	132car_SalesAndUseTaxes
Other	139us-gaap_OtherAssetsMiscellaneousCurrent	136us-gaap_OtherAssetsMiscellaneousCurrent
Total other current assets	$ 456us-gaap_OtherAssetsCurrent	$ 455us-gaap_OtherAssetsCurrent

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Sales and use taxes due either from customers arising from sales, or as previously overpaid to tax authorities.

+ References

No definition available.

+ Details

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- Definition

Aggregate carrying amount, as of the balance sheet date, of current assets not separately disclosed in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer).

+ References

Reference 1: 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

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 8

-Article 5

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- Definition

Amount of other miscellaneous assets expected to be realized or consumed within one year or operating cycle, if longer.

+ References

No definition available.

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- Definition

Amount of asset related to consideration paid in advance for costs that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Assets

-URI http://asc.fasb.org/extlink&oid=6509628

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6676-107765

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6787-107765

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 340

-SubTopic 10

-Section 05

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=47804770&loc=d3e5879-108316

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