Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs	$ 9,666	$ 9,917	$ 22,675	$ 15,749
Capitalization of interest expense	(1,656)	(1,008)	(3,047)	(1,990)
Total interest expense	8,446	9,204	20,562	14,054
Credit Agreement
Debt Instrument [Line Items]
Interest on debt instruments	77	139	216	139
Convertible Debt \| 2025 Notes
Debt Instrument [Line Items]
Interest on debt instruments	$ 359	$ 156	$ 718	$ 156

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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