Debt (Narrative) (Details)			6 Months Ended		3 Months Ended		6 Months Ended		6 Months Ended		6 Months Ended			6 Months Ended								6 Months Ended			6 Months Ended
	Jun. 30, 2012 USD ($)	Dec. 31, 2011 USD ($)	Jun. 30, 2012 2.20% Senior Notes Due 2013 [Member] USD ($) Y	Dec. 31, 2011 2.20% Senior Notes Due 2013 [Member] USD ($)	Jun. 30, 2012 3.75% Senior Notes Due 2014 [Member] USD ($) Y	Dec. 31, 2011 3.75% Senior Notes Due 2014 [Member] USD ($)	Jun. 30, 2012 2.50% Senior Notes Due 2016 [Member] USD ($) Y	Dec. 31, 2011 2.50% Senior Notes Due 2016 [Member] USD ($)	Jun. 30, 2012 4.875% Senior Notes Due 2019 [Member] USD ($) Y	Dec. 31, 2011 4.875% Senior Notes Due 2019 [Member] USD ($)	Jun. 30, 2012 1.58% Yen-Denominated Senior Notes Due 2017 [Member] USD ($) Y	Jun. 30, 2012 1.58% Yen-Denominated Senior Notes Due 2017 [Member] JPY (¥)	Dec. 31, 2011 1.58% Yen-Denominated Senior Notes Due 2017 [Member] USD ($)	Jun. 30, 2012 2.04% Yen-Denominated Senior Notes Due 2020 [Member] USD ($) Y	Jun. 30, 2012 2.04% Yen-Denominated Senior Notes Due 2020 [Member] JPY (¥)	Dec. 31, 2011 2.04% Yen-Denominated Senior Notes Due 2020 [Member] USD ($)	Jun. 30, 2012 Yen Denominated Credit Facilities [Member] USD ($)	Jun. 30, 2012 Yen Denominated Credit Facilities [Member] JPY (¥)	Dec. 31, 2011 Yen Denominated Credit Facilities [Member] USD ($)	Jun. 30, 2012 Yen Denominated Credit Facility One [Member]	Jun. 30, 2012 Yen Denominated Credit Facility Two [Member]	Jun. 30, 2012 Credit Facility [Member] USD ($)	Jun. 30, 2012 Commercial paper borrowings [Member] USD ($) D	Dec. 31, 2011 Commercial paper borrowings [Member] USD ($)	Jun. 30, 2012 Japan, Yen	Jun. 30, 2012 United States Currency Rate
Debt Instrument [Line Items]
Expected minimum principal payments in 2013	$ 531,000,000
Expected minimum principal payments in 2014	700,000,000
Expected minimum principal payments in 2015	446,000,000
Expected minimum principal payments in 2016	500,000,000
Expected minimum principal payments in 2017	102,000,000
Expected minimum principal payments thereafter	660,000,000
Issued principal amount			450,000,000		700,000,000		500,000,000		500,000,000		102,000,000	8,100,000,000	104,000,000	160,000,000	12,800,000,000	164,000,000
Debt instrument term, years			3		5		5		10		7	7		10	10
Debt instrument, stated percentage rate			2.20%		3.75%		2.50%		4.875%		1.58%	1.58%		2.04%	2.04%
Debt instrument, due date			September 2013		July 2014		January 2016		July 2019		April 28, 2017	April 28, 2017		April 28, 2020	April 28, 2020							February 2015
Debt Instrument, Description of Variable Rate Basis																									Yen LIBOR	LIBOR
Debt instrument, effective interest rate			2.23%		3.78%		2.54%		5.04%
Interest rate swap term, years			3				5
Notional amount interest rate swap designated as a fair value hedge			450,000,000				500,000,000
Proceeds from termination of interest rate swap			19,000,000				24,000,000
Net average interest rate			0.80%				1.30%
Outstanding balance under yen denominated credit facilities																	81,000,000	6,500,000,000	83,000,000
Maximum borrowing capacity																		11,250,000,000
Debt instrument basis spread																				0.275%	0.25%	0.875%
Unused borrowing capacity																						1,500,000,000
Maximum days commercial paper program provides for the issuance of short-term, unsecured commercial paper																							270
Debt	$ 2,963,000,000	$ 2,796,000,000	$ 458,000,000	$ 461,000,000	$ 700,000,000	$ 699,000,000	$ 521,000,000	$ 518,000,000	$ 495,000,000	$ 495,000,000	$ 102,000,000		$ 104,000,000	$ 160,000,000		$ 164,000,000							$ 446,000,000	$ 272,000,000
Weighted average effective interest rate																							0.23%