Stock-Based Compensation - Stock Reserved for Future Issuance (Details) shares in Thousands	Dec. 31, 2021 shares
Common stock options:
Shares reserved for future issuance	32,527
Restricted Stock Units And Performance-Based Restricted Stock Units [Member]
Common stock options:
Shares reserved for future issuance	1,678
Available for Future Grant [Member]
Common stock options:
Shares reserved for future issuance	3,359
ESPP [Member]
Common stock options:
Shares reserved for future issuance	676
1.00% Senior Convertible Notes due 2023 [Member]
Common stock options:
Shares reserved for future issuance	7,082
0.375% Senior Convertible Notes due 2025 [Member]
Common stock options:
Shares reserved for future issuance	6,512
Senior Convertible Warrants Due 2023 [Member]
Common stock options:
Shares reserved for future issuance	6,949
Senior Convertible Warrants Due 2025 [Member]
Common stock options:
Shares reserved for future issuance	6,271