Net Loss Per Share - Schedule of Basic and Diluted Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Oct. 31, 2021	Jul. 31, 2021	Apr. 30, 2021	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Oct. 31, 2021	Oct. 31, 2020
Numerator:
Net loss	$ (81,293)	$ (77,133)	$ (63,992)	$ (72,651)	$ (64,525)	$ (53,967)	$ (222,418)	$ (191,143)
Denominator:
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	66,386,379			59,368,167			63,750,884	58,476,521
Net loss per share, basic and diluted (in dollars per share)	$ (1.22)			$ (1.22)			$ (3.49)	$ (3.27)