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Equity (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions |  |  |  | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 21, 2016 | Dec. 07, 2016 | Aug. 12, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Class of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock from stock offerings, shares |  |  |  |  | 0.0 | 0.0 |
Net proceeds from sale of common stock |  |  |  |  | $ 3,187 | $ 2,623 | $ 938,268
August issuance [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock from stock offerings, shares |  |  |  | 18.4 |  |  |
Issuance of common stock, offering price per share |  |  |  | $ 30.00 |  |  |
Net proceeds from sale of common stock |  |  |  | $ 530,900 |  |  |
December issuance [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Issuance of common stock from stock offerings, shares |  |  | 10.9 |  |  |  |
Issuance of common stock, offering price per share |  |  | $ 38.25 |  |  |  |
Net proceeds from sale of common stock |  |  | $ 403,200 |  |  |  |
QStar Acquisition 2016 [Member] |  |  |  |  |  |  |
Class of Stock [Line Items] |  |  |  |  |  |  |
Private issuance of Common Stock for an acquisition |  | 13.4 |  |  |  |  |
Fair value of equity consideration | [1] | $ 437,194 |  |  |  |  |
[1] | (1) The Company issued approximately 13.4 million shares of common stock, par value $0.01 per share, in a private placement to the sellers in the QStar Acquisition on December 21, 2016. The equity consideration was valued on this date using Level 1 and Level 2 inputs with a discount applied due to the lack of marketability in the near term in accordance with the Lock-Up and Registration Rights Agreement that prohibited the sale of such stock until no earlier than the 90th day after issuance.

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