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Stockholders' Equity - Summary of Preferred and Common Stock (Parenthetical) (Details) | 9 Months Ended | 12 Months Ended
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Sep. 30, 2020 | Dec. 31, 2019
Series B 7.5% Fixed to Floating Non-Cumulative Perpetual Preferred Stock |  |
Class Of Stock [Line Items] |  |
Preferred stock, dividend rate, percentage | 7.50% | 7.50%

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- Details
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