Financial Instruments (Narrative) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Schedule of Cost-method Investments [Line Items]
Net unrealized gain (loss) on cash flow hedges					$ 2
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	7				7
Derivative Instruments, Gain (Loss) Recognized in Income, Net	(13)	[1]	37	[1]	(30)	[1]	43	[1]
Interest Rate Caps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	12,275	[2]			12,275	[2]
Interest Rate Caps [Member] | Interest Rate Caps Purchased [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 Purchased [Member] | Subsidiary Issuers [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	7,500				7,500
Interest Rate Caps [Member] | Interest Rate Caps Sold [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	9,900				9,900
Interest Rate Swaps [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	1,501				1,501
Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Units Of Gasoline	10,000,000				10,000,000
Currency Swap [Member]
Schedule of Cost-method Investments [Line Items]
Absolute notional values of derivative instruments	642				642
Not Designated As Hedging Instruments [Member] | Commodity Contracts [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	1	[3]	(2)	[3]	(29)	[4]	35	[4]
Foreign Exchange Contract [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	11		30		26		29
Operating Expense [Member]
Schedule of Cost-method Investments [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net			$ 4		$ 3		$ 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 $9.9 billion of interest rate caps sold, partially offset by approximately $2.4 billion of interest rate caps purchased. These amounts exclude $7.5 billion of interest rate caps purchased by the Company’s Avis Budget Rental Car Funding subsidiary as it is not consolidated by the Company.

[3] Included in operating expenses.

[4] For the three months ended June 30, 2014, included a $11 million loss in interest expense and for the six months ended June 30, 2014, included a $26 million loss in interest expense and a $3 million loss in operating expense. For the three months ended June 30, 2013 included a $30 million gain in interest expense and a $4 million gain in operating expense and for the six months ended June 30, 2013, included a $29 million gain in interest expense and a $6 million gain in operating expenses.