Schedule of Restructuring Costs (Detail) (2012-2014 Restructuring Program, USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period			$ 36
Charges	43	13	131	63
Cash spent	(32)		(53)
Non-cash settlements	(12)		(44)
Balance at end of period	70		70
Severance And Related Costs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period			36
Charges			99
Cash spent			(53)
Non-cash settlements	(3)	(19)	(12)	(38)
Balance at end of period	70		70
Asset Write-Downs
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period
Charges			32
Non-cash settlements			(32)
Balance at end of period