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Equity - Narrative (Details) - USD ($) | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Oct. 31, 2020 | Mar. 31, 2019 | Aug. 31, 2018 | Jul. 31, 2016
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred stock, shares authorized (in shares) | 8,000,000.0 |  |  |  |  |  |
Preferred stock, shares issued (in shares) | 0 | 0 | 0 |  |  |  |
Preferred stock, shares outstanding (in shares) | 0 | 0 | 0 |  |  |  |
Payments for repurchase of common stock | $ 6,679,100,000 | $ 5,868,300,000 | $ 4,352,600,000 |  |  |  |
Series A |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred stock, shares authorized (in shares) | 1,750,000 |  |  |  |  |  |
Series X junior participating |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred stock, shares authorized (in shares) | 1,000,000.0 |  |  |  |  |  |
Undesignated |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred stock, shares authorized (in shares) | 5,250,000 |  |  |  |  |  |
2020 Share Repurchase Program |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Authorized amount of share repurchases |  |  |  | $ 5,000,000,000.0 |  |  |
Repurchase of common stock, at cost (in shares) | 1,600,000 |  |  |  |  |  |
Payments for repurchase of common stock | $ 400,000,000.0 |  |  |  |  |  |
December 2019 Share Repurchase Program |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Authorized amount of share repurchases |  | $ 5,000,000,000.0 |  |  |  |  |
Repurchase of common stock, at cost (in shares) | 16,700,000 |  |  |  |  |  |
Payments for repurchase of common stock | $ 5,000,000,000.0 |  |  |  |  |  |
March 2019 Share Repurchase Program |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Authorized amount of share repurchases |  |  |  |  | $ 5,000,000,000.0 |  |
Repurchase of common stock, at cost (in shares) | 4,100,000 | 14,700,000 |  |  |  |  |
Payments for repurchase of common stock | $ 1,300,000,000 | $ 3,700,000,000 |  |  |  |  |
2018 Share Repurchase Program |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Authorized amount of share repurchases |  |  |  |  |  | $ 3,500,000,000 |
Repurchase of common stock, at cost (in shares) |  | 8,900,000 | 4,300,000 |  |  |  |
Payments for repurchase of common stock |  | $ 2,100,000,000 | $ 1,400,000,000 |  |  |  |
2016 Share Repurchase Program |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Authorized amount of share repurchases |  |  |  |  |  |  | $ 5,000,000,000.0
Repurchase of common stock, at cost (in shares) |  |  | 10,500,000 |  |  |  |
Payments for repurchase of common stock |  |  | $ 3,000,000,000.0 |  |  |  |

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