Basic and Diluted Net Loss Per Share - Summary of Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended				6 Months Ended
	Jul. 31, 2021	Apr. 30, 2021	Jul. 31, 2020	Apr. 30, 2020	Jul. 31, 2021	Jul. 31, 2020
Numerator:
Net income (loss)	$ (84,938)	$ 82,289	$ (35,287)	$ (30,098)	$ (2,649)	$ (65,385)
Adjust: Accretion of beneficial conversion feature of redeemable convertible preferred stock	0		58,625		0	58,625
Adjust: Cumulative dividends on redeemable convertible preferred stock	0				(4,292)
Adjust: Deemed dividends attributable to vested option holders	0				(51,855)
Adjust: Deemed dividends attributable to common stock warrant holders	0				(110,635)
Net loss attributable to common stockholders - Basic	(84,938)		(93,912)		(169,431)	(124,010)
Less: Gain attributable to earnout shares issued	0				(84,420)
Change in fair value of warrant liabilities	(7,427)				(53,540)
Net loss attributable to common stockholders - Diluted	$ (92,365)		$ (93,912)		$ (307,391)	$ (124,010)
Denominator:
Weighted average common shares outstanding	312,465,016		13,537,501		266,473,703	12,822,481
Less: Weighted-average unvested restricted shares and shares subject to repurchase	(237,490)		(68,824)		(276,221)	0
Weighted average shares outstanding - Basic	312,227,526		13,468,677		266,197,482	12,822,481
Add: Earnout Shares under the treasury stock method	0		0		7,464,203	0
Add: Public and Private Placement Warrants under the treasury stock method	1,374,574		0		1,915,315	0
Weighted average shares outstanding - Diluted	313,602,100		13,468,677		275,577,000	12,822,481
Net loss per share - Basic	$ (0.27)		$ (6.97)		$ (0.64)	$ (9.67)
Net loss per share - Diluted	$ (0.29)		$ (6.97)		$ (1.12)	$ (9.67)