Convertible Senior Notes - Schedule of Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 05, 2020
Debt Instrument [Line Items]
Amortization of debt discount and issuance costs	$ 2,143	$ 0	$ 0
Convertible notes | Convertible Senior Notes Due 2027
Debt Instrument [Line Items]
Principal amount of Convertible Senior Notes	230,000
Less: Unamortized debt discount and issuance costs	(80,647)			$ (82,800)
Net carrying amount	149,353
Equity component - net carrying value	75,333
Contractual coupon interest	1,600
Amortization of debt discount and issuance costs	2,143
Total interest expense	$ 3,743