Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	0	32,225,227
Redeemable convertible preferred stock, shares issued	0	31,968,570
Redeemable convertible preferred stock, shares outstanding	0	31,968,570
Redeemable convertible preferred stock, liquidation preference	$ 0	$ 54,415
Preferred stock, Par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	300,000,000	49,019,607
Common stock, shares issued	48,658,271	6,720,767
Common stock, shares outstanding	48,658,271	6,720,767