Net Loss Per Share - Schedule of Earnings Per Share, Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2019
Numerator:
Net loss	$ (114,979)	$ (95,940)	$ (53,885)
Denominator:
Weighted-average shares outstanding used to compute net loss per share, basic and diluted (in shares)	120,663	112,991	83,141
Net loss per share, basic and diluted (in dollars per share)	$ (0.95)	$ (0.85)	$ (0.65)