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Acquisitions and Divestitures - Narrative (Details) $ in Millions |  | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | ---
Jul. 01, 2020 USD ($) numberNewPreferredStockSeries state office shares | Dec. 31, 2020 USD ($) shares | Jun. 30, 2021 USD ($) shares | Jul. 17, 2020 USD ($) branch | Jun. 30, 2020 USD ($) | Dec. 31, 2019 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |
Number of common stock issued (in shares) | shares | 243,000,000 | 555,030,652 | 550,865,126 |  |  |
Number of new series of preferred stock | numberNewPreferredStockSeries | 3 |  |  |  |  |
Goodwill |  | $ 1,511 | $ 1,511 |  | $ 1,511 | $ 1,433
IBERIABANK (IBKC) |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Equity interest issued, value assigned | $ 2,500 |  |  |  |  |
Purchase accounting gain | 531 | 531 |  |  |  |
Goodwill | $ (531) |  |  |  |  |
Truist Bank Branches |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Number of bank branches | branch |  |  |  | 30 |  |
Goodwill |  | $ 78 |  | $ 78 |  |
IBERIABANK (IBKC) |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |
Number of offices | office | 319 |  |  |  |  |
Number of states | state | 12 |  |  |  |  |

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