CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Accounts receivable, net of allowance	$ 1,809	$ 789
Redeemable convertible preferred stock, par value	$ 0.001	$ 0.001
Redeemable convertible preferred stock, shares authorized	10,000,000	86,123,364
Redeemable convertible preferred stock, shares issued	0	83,568,628
Redeemable convertible preferred stock, shares outstanding	0	83,568,628
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	500,000,000	113,443,854
Common stock, shares issued	130,230,591	8,650,922
Common stock, shares outstanding	130,230,591	8,650,922