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Shareholders' Equity - Ordinary Shares (Details) - USD ($) $ / shares in Units, shares in Millions | 12 Months Ended | 33 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2020 | Nov. 30, 2020 | Nov. 30, 2014 | Apr. 30, 2012
Common Stock Programs [Line Items] |  |  |  |  |  |
Share repurchase authorization limit |  |  |  | $ 20,000,000,000.0 |  |
Number of shares repurchased (in shares) |  |  | 137.3 |  |  |
Costs recorded to retained earnings |  |  |  |  |  |
Total repurchase cost |  |  | $ 14,700,000,000 |  |  |
Share Repurchase Program of 2012 |  |  |  |  |  |
Common Stock Programs [Line Items] |  |  |  |  |  |
Share repurchase authorization limit |  |  |  |  |  | $ 5,000,000,000.0
Number of shares repurchased (in shares) | 8.5 | 10.5 |  |  |  |
Average price per share (in dollars per share) | $ 206.28 | $ 186.33 |  |  |  |
Costs recorded to retained earnings |  |  |  |  |  |
Total repurchase cost | $ 1,761,000,000 | $ 1,950,000,000 |  |  |  |
Additional associated costs | 2,000,000 | 10,000,000 |  |  |  |
Total costs recorded to retained earnings | 1,763,000,000 | $ 1,960,000,000 |  |  |  |
Share Repurchase Program of 2014 |  |  |  |  |  |
Common Stock Programs [Line Items] |  |  |  |  |  |
Share repurchase authorization limit |  |  |  |  | $ 5,000,000,000.0 |
Share Repurchase Program of 2017 |  |  |  |  |  |
Common Stock Programs [Line Items] |  |  |  |  |  |
Share repurchase authorization limit |  |  |  |  | $ 5,000,000,000.0 |
Costs recorded to retained earnings |  |  |  |  |  |
Remaining authorized repurchase amount | $ 5,300,000,000 |  | $ 5,300,000,000 |  |  |

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