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Equity - Narrative (Details) - USD ($) $ in Billions | 7 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Apr. 30, 2019 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2020
Equity [Abstract] |  |  |  |
Common stock, shares authorized |  | 6,500,000,000 |  | 6,500,000,000
Preferred stock, shares authorized |  |  |  | 20,000,000
Accelerated Share Repurchase Agreement, October 29, 2018 |  |  |  |
Accelerated Share Repurchases [Line Items] |  |  |  |
Purchases of treasury stock (in shares) |  |  | 56,700,000 |
Accelerated Share Repurchase Agreement |  |  |  |
Accelerated Share Repurchases [Line Items] |  |  |  |
Purchases of treasury stock (in shares) | 64,400,000 | 7,700,000 |  |
Payment under ASR agreement |  |  | $ 5 |

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- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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