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Shareholders' Equity - Ordinary Shares (Details) - USD ($) $ / shares in Units, shares in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | Nov. 30, 2014 | Apr. 30, 2012
Common Stock Programs |  |  |  |  |
Cost of shares repurchased | $ 1,550,000,000 | $ 2,250,000,000 | $ 1,102,000,000 |  |
Share Repurchase Program [Member] |  |  |  |  |
Common Stock Programs |  |  |  |  |
Number of shares repurchased (in shares) | 16.0 | 25.8 |  |  |
Average price per share of shares purchased under share repurchase program (in dollars per share) | $ 97.04 | $ 87.18 |  |  |
Cost of shares repurchased | $ 1,600,000,000 | $ 2,300,000,000 |  |  |
Share Repurchase Programs of 2012 and 2014 [Member] |  |  |  |  |
Common Stock Programs |  |  |  |  |
Share repurchase, remaining authorization limit | $ 4,100,000,000 |  |  |  |
Share Repurchase Program of 2012 [Member] |  |  |  |  |
Common Stock Programs |  |  |  |  |
Share repurchase authorization limit |  |  |  |  | $ 5,000,000,000.0
Number of shares repurchased (in shares) | 78.1 |  |  |  |
Cost of shares repurchased | $ 5,900,000,000 |  |  |  |
Share Repurchase Program of 2014 [Member] |  |  |  |  |
Common Stock Programs |  |  |  |  |
Share repurchase authorization limit |  |  |  | $ 5,000,000,000.0 |

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