Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator:
Net loss	$ (90)	$ (111)	$ (150)	$ (239)
Denominator:
Weighted-average shares used in computing net loss per share, basic	667	624	664	621
Weighted-average shares used in computing net loss per share, diluted	667	624	664	621
Net loss per share, basic	$ (0.13)	$ (0.18)	$ (0.23)	$ (0.38)
Net loss per share, diluted	$ (0.13)	$ (0.18)	$ (0.23)	$ (0.38)