Schedule of Accounts Payable and Other Current Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Accounts payable	$ 328us-gaap_AccountsPayableCurrent	$ 344us-gaap_AccountsPayableCurrent
Accrued payroll and related	229	210
Accrued sales and use taxes	194car_AccruedSalesAndUseTaxesCurrent	193car_AccruedSalesAndUseTaxesCurrent
Public liability and property damage insurance liabilities - current	121us-gaap_AccruedInsuranceCurrent	136us-gaap_AccruedInsuranceCurrent
Income taxes payable - current	89us-gaap_DeferredRevenueCurrent	87us-gaap_DeferredRevenueCurrent
Other	530us-gaap_OtherLiabilitiesCurrent	509us-gaap_OtherLiabilitiesCurrent
Accounts payable and other current liabilities	$ 1,491	$ 1,479

Accrued sales and use taxes current

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Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.

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Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable to insurance entities to mitigate potential loss from various risks or to satisfy a promise to provide certain coverage's to employees. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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The carrying amount of consideration received or receivable as of the balance sheet date on potential earnings that were not recognized as revenue in conformity with GAAP, and which are expected to be recognized as such within one year or the normal operating cycle, if longer, including sales, license fees, and royalties, but excluding interest income.

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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Aggregate carrying amount of current liabilities (due within one year or within the normal operating cycle if longer) not separately disclosed in the balance sheet. Includes costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered and of liabilities not separately disclosed.

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