Long-Term Debt - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended								3 Months Ended
	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014 Senior Notes	Dec. 31, 2013 Senior Notes	Nov. 30, 2012 Senior Notes tranche	Sep. 30, 2014 0.65% Notes due on November 27, 2015	Sep. 30, 2014 1.20% Notes due on November 29, 2017	Sep. 30, 2014 2.50% Notes due on November 29, 2022	Sep. 30, 2014 Other Long Term Debt	Dec. 31, 2013 Other Long Term Debt	Sep. 30, 2014 Maximum
Debt Instrument [Line Items]
Face amount					$ 3,000,000,000
Number of tranches of debt issued					3
Unamortized discount			20,000,000	23,000,000
Carrying amount of other long term debt including current portion	983,000,000	967,000,000
Effective interest yields						0.84%	1.38%	2.66%
Interest payment frequency			semi-annually in arrears in May and November
Total estimated fair value of notes			2,900,000,000	2,900,000,000
Long-term debt, weighted average interest rate									5.60%	5.50%
Credit Agreement, initiation date	Sep. 05, 2014
Credit Agreement, maximum borrowing capacity	2,000,000,000
Credit Agreement, term	2 years
Credit Agreement, term additional information	may be extended for up to three additional one-year terms if approved by the lenders
Credit Agreement, variable rate basis	LIBOR
Credit Agreement, basis spread on variable rate	0.625%										1.00%
Credit Agreement, borrowings outstanding	$ 0