Net Loss Per Share - Calculation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Denominator:
Weighted-average shares used in computing net loss per share, basic (in shares)	656,899	628,593
Weighted-average shares used in computing net loss per share, diluted (in shares)	656,899	628,593
Net loss per share, basic (in dollars per share)	$ (0.01)	$ (0.03)
Net loss per share, diluted (in dollars per share)	$ (0.01)	$ (0.03)
Class A
Numerator:
Net loss	$ (4,568)	$ (18,432)
Denominator:
Weighted-average shares used in computing net loss per share, basic (in shares)	568,238	534,554
Weighted-average shares used in computing net loss per share, diluted (in shares)	568,238	534,554
Net loss per share, basic (in dollars per share)	$ (0.01)	$ (0.03)
Net loss per share, diluted (in dollars per share)	$ (0.01)	$ (0.03)
Class B
Numerator:
Net loss	$ (713)	$ (3,242)
Denominator:
Weighted-average shares used in computing net loss per share, basic (in shares)	88,661	94,039
Weighted-average shares used in computing net loss per share, diluted (in shares)	88,661	94,039
Net loss per share, basic (in dollars per share)	$ (0.01)	$ (0.03)
Net loss per share, diluted (in dollars per share)	$ (0.01)	$ (0.03)