Net Loss per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net loss	$ (66,632)	$ (67,993)	$ (75,970)	$ (72,593)	$ (134,625)	$ (148,563)
Denominator:
Weighted-average common shares outstanding	71,814,232		71,094,199		71,506,216	69,792,730
Less: weighted-average common shares subject to vesting			(1,348,902)			(1,371,644)
Weighted-average common shares used to compute basic and diluted net loss per share	71,814,232		69,745,297		71,506,216	68,421,086
Net loss per share: basic and diluted	$ (0.93)		$ (1.09)		$ (1.88)	$ (2.17)