Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs	$ 46,493	$ 22,826	$ 22,040
Capitalization of interest expense	(4,533)	(3,987)	(3,402)
Total interest expense	43,202	18,839	18,638
Credit Agreement
Debt Instrument [Line Items]
Interest on debt instruments	368	0	0
Convertible Debt \| 2025 Notes
Debt Instrument [Line Items]
Interest on debt instruments	$ 874	$ 0	$ 0

Increase for accrued, but unpaid interest on the debt instrument for the period.

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Amount of the cost of borrowed funds accounted for as interest expense.

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