Convertible Senior Notes - Summary of Total Interest Expense Recognized Related To Convertible Senior Notes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
0.125% Convertible Senior Notes Due 2024
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	$ 17,974	$ 827
Total interest expense	18,538	854
0.125% Convertible Senior Notes Due 2024 | 0.125% coupon
Debt Instrument [Line Items]
Interest expense	564	27
1.50% Convertible Senior Notes Due 2022
Debt Instrument [Line Items]
Amortization of debt discount and transaction costs	4,187	4,884	$ 4,616
Total interest expense	5,550	6,593	6,341
1.50% Convertible Senior Notes Due 2022 | 1.50% Coupon
Debt Instrument [Line Items]
Interest expense	$ 1,363	$ 1,709	$ 1,725