Basic and Diluted Net Loss Per Share - Narrative (Details)	Sep. 30, 2020 $ / shares
Shares of common stock related to convertible senior notes due 2023
Earnings Per Share [Line Items]
Conversion price per share (in dollars per share)	$ 81.45
Shares related to convertible senior notes due 2025
Earnings Per Share [Line Items]
Conversion price per share (in dollars per share)	360.43
Shares related to convertible senior notes due 2026
Earnings Per Share [Line Items]
Conversion price per share (in dollars per share)	$ 424.03