Financial Instruments and Fair Value Measurements - Schedule of Reconciliation of Preferred Stock Warrant Measured at Fair Value Using Level 3 Inputs (Details) - Series F Preferred Stock Warrant $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance as of December 31, 2019	$ 1,403
Change in fair value	20,470
Conversion to common stock warrant	$ (21,873)