Stock-Based Compensation - 2013 Equity Incentive Plan Narrative (Details) - 2013 Equity Incentive Plan - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in USD per share)	$ 13.14	$ 1.63	$ 0.43
Vesting of early exercised options	$ 32.0	$ 5.1	$ 1.5
Options, exercises in period, intrinsic value	333.7	$ 27.0	$ 1.7
Cost not yet recognized, options, amount	$ 148.6
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 9 months 18 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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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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