Share-based Compensation Arrangement by Share-based Payment Award, Duration Of Offering Periods

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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- Definition

Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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- Definition

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.

+ References

No definition available.

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- Definition

The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

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- Definition

Purchase price of common stock expressed as a percentage of its fair value.

+ References

No definition available.

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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Equity Incentive Plans - 2017 Employee Stock Purchase Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018	Feb. 01, 2019	Feb. 01, 2018	Oct. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 75,776	$ 37,403	$ 21,235
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 2,200
Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares issued (in shares)	154,988	374,576	0
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for future issuance (in shares)	1,514,409					995,000
Maximum employee contribution rate	15.00%
Duration of separate offering periods	6 months
Purchase price of common stock, as a percent	85.00%
Stock-based compensation expense	$ 5,100	$ 2,900	$ 700
Employee Stock Purchase Plan \| Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Reserved for future issuance (in shares)				2,043,973	1,500,755