| **Indebtedness - (Notes)**     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
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| **Debt Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Indebtedness                   | INDEBTEDNESSTotal debt consisted of the following at December 31, net of unamortized discount and debt issuance cost: 2015 20146.0% Notes due June 2018$255 $2587.5% Senior Notes due November 2018747 7463.2% Senior Notes due August 2021746 7458.55% Debentures due June 2024149 1486.875% Notes due January 2029394 3945.125% Notes due September 20401,482 1,481Other debt268 361Total debt4,041 4,133Less:  short-term debt and current portion of long-term debt151 220Total long-term debt$3,890 $3,913The estimated fair value of total debt at December 31, 2015 and 2014 was $4,321 million and $4,663 million, respectively, which differs from the carrying amounts of $4,041 million and $4,133 million, respectively, included in our consolidated balance sheets.  The fair value was determined using quoted period end market prices.At December 31, 2015, we have a committed revolving credit facility (“credit facility”) with commercial banks and a related commercial paper program under which the maximum combined borrowing at any time under both the credit facility and the commercial paper program is $2.5 billion.  The credit facility matures in September 2016.  As of December 31, 2015, we were in compliance with all of the credit facility's covenants, and there were no direct borrowings under the credit facility during 2015.  Under the commercial paper program, we may issue from time to time up to $2.5 billion in commercial paper with maturities of no more than 270 days.  The amount available to borrow under the credit facility is reduced by the amount of any commercial paper outstanding.  At December 31, 2015, we had no borrowings outstanding under the commercial paper program.  Maturities of debt at December 31, 2015 are as follows:  2016 - $151 million; 2017 - $24 million; 2018 - $1,024 million; 2019 - $22 million; 2020 - $12 million; and $2,808 million thereafter.The weighted average interest rate on short-term borrowings outstanding at December 31, 2015 and 2014 were 12.0% and 10.0%, respectively. |

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| - Definition
The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19,20,22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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