Debt (Detail) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Debt Instrument [Line Items]
Total debt	$ 3,908	$ 3,909
Less current portion	1	1
Long-term debt	3,907	3,908
Fixed-Rate Notes Due January 2015
Debt Instrument [Line Items]
Total debt	500	500
Interest Rate	1.375%
Fixed-Rate Notes Due July 2016
Debt Instrument [Line Items]
Total debt	500	500
Interest Rate	2.25%
Fixed Rate Notes Due November Two Thousand Seventeen
Debt Instrument [Line Items]
Total debt	895	895
Interest Rate	1.00%
Fixed-Rate Notes Due July 2021
Debt Instrument [Line Items]
Total debt	499	499
Interest Rate	3.875%
Fixed Rate Notes Due November Two Thousand Twenty Two
Debt Instrument [Line Items]
Total debt	991	990
Interest Rate	2.25%
Fixed Rate Notes Due November Two Thousand Forty Two
Debt Instrument [Line Items]
Total debt	498	498
Interest Rate	3.60%
Other Debt Securities
Debt Instrument [Line Items]
Total debt	$ 25	$ 27
Other	Various