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Shareholders' Equity (Details) - USD ($) | 12 Months Ended | 69 Months Ended |  |  |
--- | --- | --- | --- | --- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2020 | Mar. 31, 2015 | Dec. 31, 2011 | Dec. 31, 2008
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock, shares authorized (shares) | 195,000,000 | 195,000,000 |  | 195,000,000 |  |  |
Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |  | $ 0.01 |  |  |
Common stock, shares issued (shares) | 97,242,318 | 96,372,182 |  | 97,242,318 |  |  |
Preferred stock, shares authorized (shares) | 5,000,000 | 5,000,000 |  | 5,000,000 |  |  |
Preferred stock, shares issued (shares) |  |  |  |  |  |  | 160,000
Conversion of convertible preferred stock (shares) | 100 |  |  | 100 |  |  |
Liquidation preference (in dollars per share) | $ 0.01 |  |  | $ 0.01 |  |  |
Authorized repurchase amount | $ 130,000,000.0 |  |  | $ 130,000,000.0 |  | $ 60,000,000.0 |
Additional repurchase amount |  |  |  |  | $ 70,000,000.0 |  |
Repurchase of common stock (shares) | 7,186,521 |  |  | 0 |  |  |
Treasury stock acquired, aggregate purchase price | $ 86,300,000 |  |  |  |  |  |
Remaining authorized repurchase amount | $ 43,700,000 |  |  | $ 43,700,000 |  |  |
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Beginning balance (shares) |  | 88,103,440 |  |  |  |  |
Ending balance (shares) |  |  | 88,103,440 |  |  |  |
Series A Convertible Preferred Stock |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Preferred stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |  | $ 0.01 |  |  |
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Beginning balance (shares) | 67,323 | 71,967 | 74,364 |  |  |  |
Conversion of convertible preferred stock (shares) | (3,734) | (4,644) | (2,397) |  |  |  |
Ending balance (shares) | 63,589 | 67,323 | 71,967 | 63,589 |  |  |
Treasury |  |  |  |  |  |  |
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Beginning balance (shares) | 7,186,521 | 7,186,521 | 7,186,521 |  |  |  |
Ending balance (shares) | 7,186,521 | 7,186,521 | 7,186,521 | 7,186,521 |  |  |
Common stock |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Common stock, shares outstanding (shares) | 90,055,797 |  |  | 90,055,797 |  |  |
Increase (Decrease) in Stockholders' Equity [Roll Forward] |  |  |  |  |  |  |
Beginning balance (shares) | 89,185,661 |  | 87,544,777 |  |  |  |
Conversion of convertible preferred stock (shares) | 373,416 | 464,431 | 239,748 |  |  |  |
Issuance for share-based compensation plans (shares) | 496,720 | 617,790 | 318,915 |  |  |  |
Ending balance (shares) | 90,055,797 | 89,185,661 |  | 90,055,797 |  |  |

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