Equity Incentive Plans - 2008 and 2016 Stock Plan (Details)	9 Months Ended
Oct. 31, 2017
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	10 years
Award vesting period	4 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
One Year Anniversary \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	25.00%
One Year Anniversary \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	25.00%
13 to 36 Months \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	75.00%
13 to 36 Months \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights percentage	75.00%
Over 10% Stockholder \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period	5 years
Minimum \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, as a percent	100.00%
Minimum \| Over 10% Stockholder \| Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Purchase price of common stock, as a percent	110.00%

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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.

+ References

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- Definition

Percentage of vesting of share-based compensation awards.

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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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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