Annual report pursuant to Section 13 and 15(d)

Debt - Schedule of Interest on Convertible Notes (Details)

v3.8.0.1
Debt - Schedule of Interest on Convertible Notes (Details) - Convertible Notes - Convertible Senior Notes Due November 2022
$ in Thousands
12 Months Ended
Dec. 31, 2017
USD ($)
Debt Instrument [Line Items]  
Contractual interest expense $ 3,119
Amortization of debt discount 5,991
Amortization of debt issuance costs 766
Total interest expense $ 9,876
Effective interest rate of the liability component 5.87%