Basic and Diluted Net Loss per Share - Computation of Basic and Diluted Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Oct. 31, 2023	Jul. 31, 2023	Apr. 30, 2023	Oct. 31, 2022	Jul. 31, 2022	Apr. 30, 2022	Oct. 31, 2023	Oct. 31, 2022
Numerator:
Net loss	$ (158,219)	$ (125,255)	$ (79,388)	$ (84,480)	$ (92,700)	$ (89,266)	$ (362,861)	$ (266,446)
Denominator:
Weighted average common shares outstanding (in shares)	376,190,781			339,674,302			360,836,403	337,135,962
Less: Weighted-average unvested restricted shares and shares subject to repurchase (in shares)	(7,998)			(78,917)			(18,272)	(98,851)
Weighted average shares outstanding - basic (in shares)	376,182,783			339,595,385			360,818,131	337,037,111
Weighted average shares outstanding - diluted (in shares)	376,182,783			339,595,385			360,818,131	337,037,111
Net loss per share - basic (in USD per share)	$ (0.43)			$ (0.25)			$ (1.01)	$ (0.79)
Net loss per share - diluted (in USD per share)	$ (0.43)			$ (0.25)			$ (1.01)	$ (0.79)