Debt (Details)				3 Months Ended	9 Months Ended
	Sep. 30, 2013 USD ($)	May 08, 2013 EUR (€)	Dec. 31, 2012 USD ($)	Sep. 30, 2013 Commercial paper [Member] USD ($)	Sep. 30, 2013 Commercial paper [Member] USD ($)	Dec. 31, 2012 Commercial paper [Member] USD ($)	Sep. 30, 2013 Securities Due July 2014 [Member] USD ($)	Sep. 30, 2013 Securities Due July 2014 [Member] EUR (€)	Apr. 15, 2013 4.250% Senior notes due 2042 [Member] USD ($)	Mar. 08, 2013 4.250% Senior notes due 2042 [Member] USD ($)	Dec. 12, 2012 4.250% Senior notes due 2042 [Member] USD ($)	May 21, 2013 4.45% notes due 2043 [Member] USD ($)
Debt Instrument
Total debt				$ 511,000,000	$ 511,000,000	$ 50,000,000
Weighted average commercial paper outstanding				524,000,000	349,000,000
Weighted-average interest rates (as a percent)				0.33%	0.35%
Short-term debt and current portion of long-term debt	1,206,000,000		452,000,000				674,000,000	500,000,000
Face amount of debt									256,000,000	90,000,000		250,000,000
Stated interest rate									4.25%	4.25%	4.25%	4.45%
Short-term debt aggregate principal amount											166,000,000
Credit facility maximum borrowing amount		€ 650,000,000