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Shareholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions |  | 3 Months Ended |
--- | --- | --- | ---
May 24, 2019 | Jun. 30, 2020 | Dec. 31, 2019
Class of Stock [Line Items] |  |  |
Common stock, authorized shares (in shares) |  | 500,000,000 | 500,000,000
Common stock, par value (in dollars per share) |  | $ 0.01 | $ 0.01
Common stock, issued shares (in shares) |  | 101,434,104 | 89,682,387
Common stock, outstanding shares (in shares) |  | 101,434,104 | 89,682,387
Offering price per share (in dollars per share) | $ 26.00 | $ 23.25 |
Payments of stock issuance costs | $ 16.0 | $ 13.4 |
Preferred stock, authorized (in shares) |  | 200,000,000 |
Preferred stock, par value (in dollars per share) |  | $ 0.01 |
Preferred stock, shares issued (in shares) |  | 0 |
Preferred stock, shares outstanding (in shares) |  | 0 |
Convertible debt securities |  |  |
Class of Stock [Line Items] |  |  |
Common stock shares reserved for issuance (in shares) |  | 11,492,280 |
Common stock options |  |  |
Class of Stock [Line Items] |  |  |
Common stock shares reserved for issuance (in shares) |  | 13,271,513 |
Unvested restricted stock and RSUs |  |  |
Class of Stock [Line Items] |  |  |
Common stock shares reserved for issuance (in shares) |  | 868,210 |
Public Stock Offering |  |  |
Class of Stock [Line Items] |  |  |
Shares sold in offering | 10,657,692 | 11,155,000 |
Aggregate net proceeds from stock offering | $ 261.1 | $ 245.9 |
Over-Allotment Option |  |  |
Class of Stock [Line Items] |  |  |
Shares sold in offering | 1,042,307 | 1,455,000 |
Public Stock Offering - Shares From Company's Chairman and Chief Executive Officer |  |  |
Class of Stock [Line Items] |  |  |
Shares sold in offering | 400,000 |  |

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