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Debt - Schedule of Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Debt Instrument [Line Items]
Interest Expense	$ 2,378	$ 888	$ 3,188	$ 1,770
Convertible Senior Notes \| Convertible debt
Debt Instrument [Line Items]
Interest Expense, Debt			48
Amortization of Debt Discount (Premium)			1,582
Amortization of Debt Issuance Costs			151
Interest Expense			$ 1,781