Valuation And Qualifying Accounts (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011		Dec. 31, 2010
Allowance for Doubtful Accounts
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	$ 21	$ 16		$ 14
Expensed	27	9		6
Other Adjustments				1
Deductions	(8)	(4)		(5)
Balance at End of Period	40	21		16
Tax Valuation Allowance
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at Beginning of Period	273	192		166
Expensed	25	16		26
Other Adjustments		65	[1]
Balance at End of Period	$ 298	$ 273		$ 192

[1] For 2011, other adjustments relate to the acquisition of Avis Europe.