Stock-Based Compensation - 2013 Equity Incentive Plan Narrative (Details) - 2013 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Oct. 31, 2021	Oct. 31, 2020	Oct. 31, 2021	Oct. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	0		14,048,623
Weighted average grant date fair value (in USD per share)		$ 2.25	$ 13.14	$ 1.52
Vesting of early exercised options	$ 9,100	$ 1,400	$ 21,400	$ 3,400
Options, exercises in period, intrinsic value	92,700	$ 6,800	173,600	$ 8,700
Cost not yet recognized, options, amount	$ 162,900		$ 162,900
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period			10 years
Vesting percentage			25.00%
Award vesting period			3 years
Cost not yet recognized, period for recognition			2 years 10 months 24 days

Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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Amount of cost to be recognized for option under share-based payment arrangement.

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Gross number of share options (or share units) granted during the period.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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Percentage of vesting of award under share-based payment arrangement.

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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Fair value of options vested. Excludes equity instruments other than options, for example, but not limited to, share units, stock appreciation rights, restricted stock.

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