Acquisitions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended					3 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2012 Maximum Customer Relationships	Dec. 31, 2011 Avis Europe	Dec. 31, 2012 Avis Europe	Dec. 31, 2011 Avis Europe	Dec. 31, 2012 Avis Europe Licensee And Sub Licensee Agreements	Dec. 31, 2012 Avis Europe Customer Relationships	Dec. 31, 2012 Apex Car Rentals Vehicle	Dec. 31, 2012 Apex Car Rentals Maximum	Dec. 31, 2012 Zipcar
Business Acquisition [Line Items]
Date of acquisition								Oct. 03, 2011			Oct. 01, 2012
Rental cars											4,000
Acquisition cash paid											$ 63
Contingent consideration with an estimated acquisition date fair value											9
Contingent consideration additional payments												26
Vehicles							91				33
Trademarks											21
Goodwill							290				16
Acquisition purchase price						976	976	976
Repaid acquired indebtedness								649
Loss on unfavorable master license agreement							117
Acquisition, other intangibles									188	66
Other intangibles, useful life, in years					20 years				20 years	12 years
Net revenues	7,357	5,900		5,185		359
Net loss	290	(29)	[1]	54		223
Transaction-related costs	34	255		14		213		213
Business acquisition, purchase price													$ 500

[1] As the Company incurred a net loss in 2011, all outstanding stock options, restricted stock units, stock warrants and issuable shares underlying the convertible notes have an anti-dilutive effect and therefore are excluded from the computation of diluted weighted average shares outstanding. Accordingly, basic and diluted weighted average shares outstanding are equal for such period.