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Equity Plans and Stock-based Compensation - Additional Information (Detail) - USD ($)	3 Months Ended
	Apr. 30, 2021	Apr. 30, 2020	Jan. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	29,795,964		30,166,792
Stock based compensation expense	$ 7,577,000	$ 910,000
Total unrecognized stock based compensation cost related to stock awards	$ 45,000,000
Weighted average period	2 years 1 month 6 days
Common stock capital shares reserved for future issuance	132,298,260
CEO Awards Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 0
Total compensation cost related to unvested awards not yet recognised	$ 38,800,000
Equity Incentive Plan Two Thousand Twenty One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement, shares available for grant	41,429,526
Share based compensation, terms of plan	On the first day of each March, beginning on March 1, 2021 and continuing through March 1, 2030, the 2021 EIP reserve will automatically increase by a number of shares equal to the lesser of (a) 5% of the total number of shares actually issued and outstanding on the last day of the preceding month and (b) a number determined by our Board of Directors.
Equity Stock Purchase Plan Two Thousand Twenty One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement, shares available for grant	8,177,683
Share based compensation, terms of plan	on the first day of each March during the term of the 2021 ESPP, commencing on March 1, 2021 and ending on (and including) March 1, 2040, the aggregate number of shares of stock that may be issued under the 2021 ESPP shall automatically increase by a number equal to the lesser of (i) one percent (1%) of the total number of shares of stock issued and outstanding on the last day of the preceding month, (ii) 5,400,000 shares of stock (subject to standard anti-dilution adjustments), or (iii) a number of shares of stock determined by the Board.
Share based compensation arrangement, description of plan	Under the 2021 ESPP, the Company can grant stock options to purchase shares of Common Stock at a purchase price which shall not be less either than 85% of the fair market value of such share on the first trading day of an offering period or 85% of the fair market value of such share on the purchase date.
Equity Incentive Plan Two Thousand Seventeen [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock capital shares reserved for future issuance	24,259,238
Equity Incentive Plan Two Thousand Seven [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock capital shares reserved for future issuance	5,143,849
Chief Executive Officer [Member] \| CEO Awards Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding	1,500,000