Convertible Notes - Equity and Liability Components (Details) - Convertible Notes Payable [Member] - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 23, 2019
Debt Instrument [Line Items]
Principal amount	$ 80,500	$ 80,500
Unamortized discount	(20,908)
Unamortized issuance costs	(2,328)	$ (3,500)
Total convertible senior notes	57,264
Equity component , net of issuance costs	$ 21,662