Net Income Loss Per Share Attributable to Common Stockholders - Summary of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020
Numerator:
Net loss	$ (239,663)	$ (52,840)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	215,352	159,003
Net loss per share attributable to common stockholders, basic and diluted	$ (1.11)	$ (0.33)
Class A Common Stock
Numerator:
Net loss	$ (120,397)	$ (14,377)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	108,184	43,261
Net loss per share attributable to common stockholders, basic and diluted	$ (1.11)	$ (0.33)
Class B Common Stock
Numerator:
Net loss	$ (119,266)	$ (38,463)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted	107,168	115,742
Net loss per share attributable to common stockholders, basic and diluted	$ (1.11)	$ (0.33)