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 | ||||||||||||||||||||||||||||||||||||