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Shareholders' Equity (Details) (USD $) | 1 Months Ended | 3 Months Ended | 9 Months Ended | 30 Months Ended
--- | --- | --- | --- | ---
Apr. 30, 2012 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014
Common Stock Programs |  |  |  |  |  |  |  |  |  |
Total cost of shares purchased |  |  |  |  |  | $ 1,750,000,000 |  |  |  |
Weighted average shares outstanding |  |  |  |  |  |  |  |  |  |
Shares for basic earnings per share (in shares) |  | 292,300,000 | [1] | 309,500,000 | [1] | 298,100,000 | [1] | 313,200,000 | [1] |
Common stock equivalents (in shares) |  | 3,800,000 |  | 3,400,000 |  | 3,500,000 |  | 3,500,000 |  |
Shares for diluted earnings per share (in shares) |  | 296,100,000 |  | 312,900,000 |  | 301,600,000 |  | 316,700,000 |  |
Number of participating securities (in shares) |  | 2,900,000 |  | 3,800,000 |  | 3,100,000 |  | 4,000,000 |  |
Number of shares excluded from the calculation of diluted earnings per share |  | 0 |  | 0 |  | 0 |  | 0 |  |
2012 - Share Repurchase Program [Member] |  |  |  |  |  |  |  |  |  |
Common Stock Programs |  |  |  |  |  |  |  |  |  |
Share repurchase authorization limit | 5,000,000,000 |  |  |  |  |  |  |  |  |
Shares purchased (in shares) |  | 5,800,000 |  | 7,300,000 |  | 20,400,000 |  | 15,800,000 |  | 56,700,000
Average price per share of stock repurchased |  | $ 86.07 |  | $ 68.33 |  | $ 85.73 |  | $ 64.79 |  |
Total cost of shares purchased |  | 500,000,000 |  | 500,000,000 |  | 1,800,000,000 |  | 1,000,000,000 |  | 3,900,000,000
Share repurchase, remaining authorization limit |  |  |  |  |  | $ 1,100,000,000 |  |  |  |
[1] | Includes 2.9 million and 3.8 million of participating securities for the three months ended September 30, 2014 and 2013, respectively, and 3.1 million and 4.0 million of participating securities for the nine months ended September 30, 2014 and 2013, respectively.

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- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Antidilution -URI http://asc.fasb.org/extlink&oid=6505113 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Diluted Earnings Per Share -URI http://asc.fasb.org/extlink&oid=6510752 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Contingent Stock Agreement -URI http://asc.fasb.org/extlink&oid=6508534 + Details
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