Financial Instruments (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Schedule of Cost-method Investments [Line Items]
Gain (Loss) on Derivative Used in Net Investment Hedge, Net of Tax	$ 8
Cash posted as collateral for derivatives in a liability position	3				3
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(15)	[1]	(4)	[1]	28	[1]	2	[1]
Interest Rate Caps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	6,959	[2]			6,959	[2]
Interest Rate Caps [Member] | Interest Rate Caps Purchased [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	2,200				2,200
Interest Rate Caps [Member] | Interest Rate Caps Purchased [Member] | Subsidiary Issuers [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	2,500				2,500
Interest Rate Caps [Member] | Interest Rate Caps Sold [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	4,700				4,700
Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	904				904
Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	77				77
Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Units Of Gasoline	11,000,000				11,000,000
Foreign Exchange Contract [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	704				704
Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(13)	[3]	(2)	[3]	22	[3]	0	[3]
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	0	[4]	3	[4]	0	[4]	4	[4]
Interest Expense [Member] | Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	16				13
Operating Expense [Member] | Not Designated As Hedging Instruments [Member] | Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments Gain Loss Recognized In Operations	$ 3				$ 9

[1] Gains (losses) related to derivative instruments are expected to be largely offset by (losses) gains on the underlying exposures being hedged.

[2] Represents $4.7 billion of interest rate caps sold and approximately $2.2 billion of interest rate caps purchased. These amounts exclude $2.5 billion of interest rate caps purchased by the Company’s Avis Budget Rental Car Funding (AESOP) LLC (“Avis Budget Rental Car Funding”) subsidiary.

[3] For the three months ended September 30, 2013, included a $16 million loss in interest expense and a $3 million gain in operating expenses. For the nine months ended September 30, 2013, included a $13 million gain in interest expense and a $9 million gain in operating expenses. For the three and nine months ended September 30, 2012, amounts were included in operating expenses.

[4] Included in operating expense.