Restructuring and Other Charges - Activity and Reserve Balances for Restructuring Charges (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	$ 111	$ 134
Cash payments	(15)	(57)
Restructuring charges	4	60
Other	(4)	(26)
Restructuring reserve ending balance	96	111
Layoff Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	59	77
Cash payments	(12)	(44)
Restructuring charges	3	47
Other	(4)	(21)
Restructuring reserve ending balance	46	59
Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	52	57
Cash payments	(3)	(13)
Restructuring charges	1	13
Other		(5)
Restructuring reserve ending balance	$ 50	$ 52