Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Series A convertible preferred stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	100,000,000	32,133,287
Convertible preferred stock, shares issued	0	5,305,513
Convertible preferred stock, shares outstanding	0	5,305,513
Convertible preferred stock, aggregate liquidation preference	$ 58,892	$ 58,892
Series B convertible preferred stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	100,000,000	18,008,749
Convertible preferred stock, shares issued	0	3,001,421
Convertible preferred stock, shares outstanding	0	3,001,421
Convertible preferred stock, aggregate liquidation preference	$ 35,000	$ 35,000
Series C1 convertible preferred stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	50,000,000	54,184,549
Convertible preferred stock, shares issued	0	5,007,134
Convertible preferred stock, shares outstanding	0	5,007,134
Convertible preferred stock, aggregate liquidation preference	$ 70,000	$ 70,000
Series C2 convertible preferred stock
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	50,000,000	23,605,150
Convertible preferred stock, shares issued	0	3,934,191
Convertible preferred stock, shares outstanding	0	3,934,191
Convertible preferred stock, aggregate liquidation preference	$ 55,000	$ 55,000
Class A common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	650,000,000	191,398,492
Common stock, shares issued	22,035,976	2,119,872
Common stock, shares outstanding	22,035,976	2,119,872
Class B common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	50,000,000	23,605,150
Common stock, shares issued	5,934,191	0
Common stock, shares outstanding	5,934,191	0