Pension Plans, Other Postretirement Benefits, and Defined-Contribution Plans - Change in Plan Assets, Funded Status of the Plans, and Amounts Recognized in the Financial Statements (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Change in plan assets
Fair value of plan assets at beginning of year	$ 1,308	$ 1,104
Actual return on plan assets	159	(4)
Employer contributions	107	311
Participant contributions	1	1
Benefit payments	(117)	(103)
Foreign-currency exchange-rate changes	4	(1)
Fair value of plan assets at end of year	1,462	1,308
Funded status of the plans at end of year	(835)	(716)
Total recognized amounts in the balance sheet consist of
Other assets	30	11
Accrued expenses	(44)	(33)
Other long-term liabilities - other	(821)	(694)
Total	(835)	(716)
Total recognized amounts in accumulated other comprehensive income consist of
Prior service cost (credit)	(2)	(2)
Net actuarial (gain) loss	916	853
Total	914	851
Other Postretirement Benefit Plans, Defined Benefit [Member]
Change in plan assets
Employer contributions	19	17
Participant contributions	3	4
Benefit payments	(22)	(21)
Funded status of the plans at end of year	(359)	(354)
Total recognized amounts in the balance sheet consist of
Accrued expenses	(16)	(18)
Other long-term liabilities - other	(343)	(336)
Total	(359)	(354)
Total recognized amounts in accumulated other comprehensive income consist of
Prior service cost (credit)	3	5
Net actuarial (gain) loss	(4)	(4)
Total	$ (1)	$ 1