Restructuring and Other Charges - Activity and Reserve Balances for Restructuring Charges (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	$ 111	$ 134
Cash payments	(25)	(57)
Restructuring charges	98	60
Other	(76)	(26)
Restructuring reserve ending balance	108	111
Layoff Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	59	77
Cash payments	(19)	(44)
Restructuring charges	27	47
Other	(7)	(21)
Restructuring reserve ending balance	60	59
Other exit costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring reserve beginning balance	52	57
Cash payments	(6)	(13)
Restructuring charges	71	13
Other	(69)	(5)
Restructuring reserve ending balance	$ 48	$ 52