Deferred Income Tax Assets And Liabilities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Deferred Income Tax Assets And Liabilities [Line Items]
Accrued liabilities and deferred income	$ 179		$ 175
Provision for doubtful accounts	10		9
Acquisition and integration-related liabilities	8		8
Convertible note hedge	3		7
Valuation allowance	(22)	[1]	(45)	[1]
Current deferred income tax assets	178		154
Accrued liabilities and deferred income	6		8
Prepaid expenses	26		26
Current deferred income tax liabilities	32		34
Current net deferred income tax assets	146		120
Net tax loss carryforwards	1,454	[2]	358	[2]
Accrued liabilities and deferred income	151		155
Depreciation and amortization	54		74
Tax credits	62		62
Convertible note hedge	2		13
Acquisition and integration-related liabilities	16		18
Other	36		39
Valuation allowance	(276)	[1]	(228)	[1]
Non-current deferred income tax assets	1,499		491
Depreciation and amortization	42		43
Other	3		4
Non-current deferred income tax liabilities	45		47
Non-current net deferred income tax assets	1,454		444
Vehicle Programs
Deferred Income Tax Assets And Liabilities [Line Items]
Depreciation and amortization	49		35
Unrealized hedge loss			8
Deferred income tax assets	49		43
Depreciation and amortization	2,212		1,025
Deferred income tax liabilities	2,212		1,025
Net deferred income tax liabilities under vehicle programs	$ 2,163		$ 982

[1] The valuation allowance of $298 million at December 31, 2012 relates to tax loss carryforwards, foreign tax credits and certain state deferred tax assets of $227 million, $53 million and $18 million, respectively. The valuation allowance will be reduced when and if the Company determines it is more likely than not that the related deferred income tax assets will be realized. The valuation allowance of $273 million at December 31, 2011 relates to tax loss carryforwards, foreign tax credits and certain state deferred tax assets of $195 million, $53 million and $25 million, respectively. The valuation allowance will be reduced when and if the Company determines it is more likely than not that the related deferred income tax assets will be realized.

[2] The increase in net tax loss carryforwards is primarily due to an increase in U.S. federal net operating losses as a result of accelerated tax depreciation on vehicles.