Convertible Senior Notes - Summary of Fair Value and Carrying Value of Convertible Senior Notes (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
0% Convertible Senior Notes Due 2026 | Fair Value
Debt Instrument [Line Items]
Convertible senior notes	$ 369,000
0% Convertible Senior Notes Due 2026 | Carrying Value
Debt Instrument [Line Items]
Convertible senior notes	263,080
0.125% Convertible Senior Notes Due 2024 | Fair Value
Debt Instrument [Line Items]
Convertible senior notes	585,000	$ 663,615
0.125% Convertible Senior Notes Due 2024 | Carrying Value
Debt Instrument [Line Items]
Convertible senior notes	373,672	369,032
1.50% Convertible Senior Notes Due 2022 | Fair Value
Debt Instrument [Line Items]
Convertible senior notes	7,170	265,488
1.50% Convertible Senior Notes Due 2022 | Carrying Value
Debt Instrument [Line Items]
Convertible senior notes	$ 1,413	$ 72,482