Notes Payable - Convertible Senior Notes - Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Aug. 31, 2019	Jun. 30, 2015
Liability component:
Less: unamortized debt discount		$ (61,641)
Less: unamortized debt issuance costs	$ (4,150)	(4,867)
Net carrying amount	395,850	454,191
Total equity component		112,309
2.25% Convertible Senior Notes due 2022
Liability component:
Total equity component		19,807
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued		120,699		$ 335,700
Less: unamortized debt discount		(3,500)
0.75% Convertible Senior Notes due 2024
Liability component:
Total equity component		41,152
0.75% Convertible Senior Notes due 2024 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued	200,000	200,000	$ 200,000
Less: unamortized debt discount		(22,300)
1.50% Convertible Senior Notes due 2026
Liability component:
Total equity component		51,350
1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Liability component:
Aggregate principal amount of notes issued	$ 200,000	200,000	$ 200,000
Less: unamortized debt discount		$ (35,800)