Financial Instruments (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Schedule of Cost-method Investments [Line Items]
Gain (Loss) on Derivative Used in Net Investment Hedge, Net of Tax	$ 3
Cash posted as collateral for derivatives in a liability position	5				5
Derivative Instruments, Gain (Loss) Recognized in Income, Net	37	[1]	2	[1]	43	[1]	6	[1]
Interest Rate Caps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	6,798	[2]			6,798	[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	2,400				2,400
Interest Rate Caps [Member] | Interest Rate Caps Sold [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	4,600				4,600
Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	793				793
Foreign Exchange Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	554				554
Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Units Of Gasoline	6,000,000				6,000,000
Foreign Exchange Contract [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	492				492
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	34	[3]	6	[3]	35	[3]	2	[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	(2)	[4]	(5)	[4]	0	[4]	1	[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	30				29
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	$ 4				$ 6

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

[2] Represents $4.6 billion of interest rate caps sold, partially offset by approximately $2.2 billion of interest rate caps purchased, which amount excludes $2.4 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 June 30, 2013, included a $30 million gain in interest expense and a $4 million gain in operating expenses. For the six months ended June 30, 2013, included a $29 million gain in interest expense and a $6 million gain in operating expenses. For the three and six months ended June 30, 2012, amounts were included in operating expenses.

[4] Included in operating expense.