Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Redeemable convertible preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Redeemable convertible preferred stock, shares authorized (in shares)	0	227,328,900
Redeemable convertible preferred stock, shares issued (in shares)	0	219,175,709
Redeemable convertible preferred stock, shares outstanding (in shares)	0	219,175,709
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	1,000,000,000	0
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	0	340,000,000
Common stock, shares issued (in shares)	0	22,438,472
Common stock, shares outstanding (in shares)	0	22,438,472
Class A Common Stock
Common stock, shares authorized (in shares)	18,000,000,000	0
Common stock, shares issued (in shares)	293,793,151	0
Common stock, shares outstanding (in shares)	293,793,151	0
Class B Common Stock
Common stock, shares authorized (in shares)	100,000,000	0
Common stock, shares issued (in shares)	8,802,629	0
Common stock, shares outstanding (in shares)	8,802,629	0