Notes Payable - Convertible Senior Notes Due 2022, Convertible Senior Notes Due 2024 and Convertible Senior Notes Due 2026 (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Aug. 31, 2019	Jun. 30, 2015	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Notes Payable
Unamortized debt discount							$ 61,641
Non-cash interest expense			$ 1,524	$ 7,841	$ 6,072	$ 23,199
2.25% Convertible Senior Notes due 2022 | Convertible Senior Notes
Notes Payable
Debt issuance costs incurred		$ 11,700
Debt issuance costs allocated to equity components		4,000
Debt issuance costs allocated to liability components		$ 7,700
Debt instrument term		7 years
Effective interest rate on liability components			2.70%		2.70%
Unamortized debt discount							3,500
Non-cash interest expense				1,800		5,400
0.75% Convertible Senior Notes due 2024 and 1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Debt issuance costs incurred	$ 9,000
Debt issuance costs allocated to equity components	2,100
Debt issuance costs allocated to liability components	$ 6,900
0.75% Convertible Senior Notes due 2024 | Convertible Senior Notes
Notes Payable
Debt instrument term	5 years
Effective interest rate on liability components			1.20%		1.20%
Unamortized debt discount							22,300
Non-cash interest expense				2,100		6,100
1.50% Convertible Senior Notes due 2026 | Convertible Senior Notes
Notes Payable
Debt instrument term	7 years
Effective interest rate on liability components			1.90%		1.90%
Unamortized debt discount							$ 35,800
Non-cash interest expense				$ 1,700		$ 5,100