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Stockholders' Equity - Authorized and Outstanding Equity (Details) | Sep. 30, 2020 vote $ / shares shares | Dec. 31, 2019 $ / shares shares
--- | --- | ---
Class of Stock [Line Items] |  |
Common stock, shares, outstanding | 78,575,100 | 77,801,854
Restricted Stock |  |
Class of Stock [Line Items] |  |
Unvested - Number of awards (in shares) | 5,296,632 | 5,005,422
Holdings GP Units | Restricted Stock |  |
Class of Stock [Line Items] |  |
Unvested - Number of awards (in shares) | 5,186,737 |
Class A Common Stock |  |
Class of Stock [Line Items] |  |
Common stock, par value per share (in dollars per share) | $ / shares | $ 0.01 | $ 0.01
Common stock, shares authorized (in shares) | 500,000,000 | 500,000,000
Common stock, shares, outstanding | 61,425,521 | 56,429,825
Common stock votes per share | vote | 1 |
Class B Common Stock |  |
Class of Stock [Line Items] |  |
Common stock, par value per share (in dollars per share) | $ / shares | $ 0.01 | $ 0.01
Common stock, shares authorized (in shares) | 200,000,000 | 200,000,000
Common stock, shares, outstanding | 5,519,415 | 7,803,364
Common stock votes per share | vote | 1 |
Class C Common Stock |  |
Class of Stock [Line Items] |  |
Common stock, par value per share (in dollars per share) | $ / shares | $ 0.01 | $ 0.01
Common stock, shares authorized (in shares) | 400,000,000 | 400,000,000
Common stock, shares, outstanding | 11,630,164 | 13,568,665
Common stock votes per share | vote | 1 |

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