Fair Value Measurements - Schedule of Changes in Fair Value of Level 3 Financial Instruments (Details) - Fair Value Level 3 - Measure of Changes in Fair Value - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Redeemable Convertible Preferred Stock Tranche Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, beginning balance		$ 3,113	$ 8,557
Change in the fair value included in other income (expense), net		(1,970)	(4,542)
Exercise			(902)
Termination		(1,143)
Fair value, ending balance			3,113
TRDF Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, beginning balance		142	136
Settlement		(88)
Change in the fair value included in other income (expense), net		(54)	6
Fair value, ending balance			$ 142
Redeemable Convertible Preferred Stock Warrant Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value, beginning balance	$ 1,881
Recognition of preferred stock warrant liabilities	144	2,131
Change in the fair value included in other income (expense), net	897	(250)
Conversion of convertible preferred stock warrant into common stock warrant in connection with Merger	(2,922)
Fair value, ending balance		$ 1,881
Contingent Consideration Liability
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Recognition of contingent consideration liability	2,880
Change in the fair value included in research and development expense	(1,900)
Fair value, ending balance	$ 980