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Equity Awards and Instruments - Stock Grants Narrative (Details) - shares | 9 Months Ended
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Sep. 30, 2020 | Sep. 30, 2019
Class B Common Stock | 2020 Incentive Award Plan |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |
Fully vested shares granted (in shares) | 17,411 | 0

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