Net Loss Per Share Attributable to Common Stockholders - EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (163,929)	$ (47,695)	$ (58,200)
Deemed dividend to redeemable convertible preferred stockholders	0	0	(64,149)
Net loss attributable to Class A and Class B common stockholders	$ (163,929)	$ (47,695)	$ (122,349)
Weighted-average shares used in computing net loss per share attributable to common stockholders - Diluted (in shares)	362,756,466	122,932,556	113,851,714
Weighted-average shares used in computing net loss per share attributable to common stockholders - Basic (in shares)	362,756,466	122,932,556	113,851,714
Net loss per share attributable to common stockholders, basic (in dollars per share)	$ (0.45)	$ (0.39)	$ (1.07)
Net loss per share attributable to common stockholders, diluted (in dollars per share)	$ (0.45)	$ (0.39)	$ (1.07)