Long-term Debt and Credit Agreements (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended		3 Months Ended					3 Months Ended															9 Months Ended		9 Months Ended												9 Months Ended
	Mar. 31, 2011	Feb. 28, 2011	Mar. 31, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2011 Notes 6.125% Due 2011 [Member]	Dec. 31, 2010 Notes 6.125% Due 2011 [Member]	Mar. 31, 2011 Notes 5.625% Due 2012 [Member]	Sep. 30, 2011 Notes 5.625% Due 2012 [Member]	Dec. 31, 2010 Notes 5.625% Due 2012 [Member]	Sep. 30, 2011 Notes 4.25% Due 2013 [Member]	Dec. 31, 2010 Notes 4.25% Due 2013 [Member]	Sep. 30, 2011 Notes 3.875% Due 2014 [Member]	Dec. 31, 2010 Notes 3.875% Due 2014 [Member]	Sep. 30, 2011 Notes 5.40% Due 2016 [Member]	Dec. 31, 2010 Notes 5.40% Due 2016 [Member]	Sep. 30, 2011 Notes 5.30% Due 2017 [Member]	Dec. 31, 2010 Notes 5.30% Due 2017 [Member]	Sep. 30, 2011 Notes 5.30% Due 2018 [Member]	Dec. 31, 2010 Notes 5.30% Due 2018 [Member]	Sep. 30, 2011 Notes 5.0% Due 2019 [Member]	Dec. 31, 2010 Notes 5.0% Due 2019 [Member]	Sep. 30, 2011 Notes 4.25% Due 2021 [Member]	Dec. 31, 2010 Notes 4.25% Due 2021 [Member]	Sep. 30, 2011 Notes 5.375% Due 2041 [Member]	Dec. 31, 2010 Notes 5.375% Due 2041 [Member]	Sep. 30, 2011 Industrial Development Bond Obligations, Floating Rate Maturing At Various Dates Through 2037 [Member]	Dec. 31, 2010 Industrial Development Bond Obligations, Floating Rate Maturing At Various Dates Through 2037 [Member]	Sep. 30, 2011 Debentures 6.625% Due 2028 [Member]	Dec. 31, 2010 Debentures 6.625% Due 2028 [Member]	Sep. 30, 2011 Debentures 9.065% Due 2033 [Member]	Dec. 31, 2010 Debentures 9.065% Due 2033 [Member]	Sep. 30, 2011 Notes 5.70% Due 2036 [Member]	Dec. 31, 2010 Notes 5.70% Due 2036 [Member]	Sep. 30, 2011 Notes 5.70% Due 2037 [Member]	Dec. 31, 2010 Notes 5.70% Due 2037 [Member]	Sep. 30, 2011 Other (including capitalized leases), .6% to 9.5% maturing at various dates through 2023 [Member]	Dec. 31, 2010 Other (including capitalized leases), .6% to 9.5% maturing at various dates through 2023 [Member]
Debt Instrument [Line Items]
Senior Notes						$ 500	$ 500		$ 0	$ 400	$ 600	$ 600	$ 600	$ 600	$ 400	$ 400	$ 400	$ 400	$ 900	$ 900	$ 900	$ 900	$ 800	$ 0	$ 600	$ 0							$ 550	$ 550	$ 600	$ 600
Industrial Development Bond																											37	46
Debentures																													216	216	51	51
Other, including capitalized leases																																					241	115
Total Long-term debt				7,395	6,278
Less current portion				(515)	(523)
Total Noncurrent Debt				6,880	5,755
Various interest rates						6.125%			5.625%		4.25%		3.875%		5.40%		5.30%		5.30%		5.00%		4.25%		5.375%				6.625%		9.065%		5.70%		5.70%
Interest rate range minimum																																					0.60%
Interest rate range maximum																																					9.50%
Repayment Of Notes								400
Proceeds From Issuance Of Long Term Debt		1,400
Date of issuance																							February 2011		February 2011
Long-Term Debt, by Maturity [Abstract]
2011				514
2012				17
2013				618
2014				607
2015				1
Thereafter				5,638
Total Long-term debt				7,395	6,278
Less current portion				(515)	(523)
Total Long-term debt				6,880	5,755
Long Term Debt And Credit Agreements Paragraph Details [Abstract]
Payments Of Debt Extinguishment Costs			29
Payments Of Debt Issuance Costs		19
Line Of Credit Facility Current Borrowing Capacity	2,800		2,800
Line Of Credit Facility Maximum Borrowing Capacity	3,500		3,500
Line Of Credit Facility Borrowing Capacity Description	The Credit Agreement is maintained for general corporate purposes, including support for the issuance of commercial paper
Line Of Credit Facility Expired	$ 2,800		$ 2,800