Stockholders' Deficit - Additional Information (Detail) - USD ($)	6 Months Ended
Aug. 31, 2016	Sep. 30, 2015
2015 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Stock Purchase Plan, offering period	6 months
Employee Stock Purchase Plan, percentage	85.00%
Number of common stock shares reserved for issuance (in shares)	715,230
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and RSUs granted vesting period	4 years
Unrecognized compensation cost related to outstanding stock options	$ 12,800,000
Expected period for recognizing compensation expense	2 years 3 months 10 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options and RSUs granted vesting period	4 years
Expected period for recognizing compensation expense	2 years 9 months 28 days
Unrecognized compensation cost related to unvested RSUs	$ 49,400,000
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted are exercisable for periods	10 years
Common stock repurchase program, aggregate purchase price		$ 50,000,000
Maximum \| 2015 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common stock shares reserved for issuance (in shares)	750,000

Share-based Compensation Arrangement By Share-based Payment Award, Offering Period

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- Definition

Aggregate number of common shares reserved for future issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29)
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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, 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 (i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

No definition available.

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- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
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-Section 50
-Paragraph 2
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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.

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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=6415400&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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- Definition

Amount of stock repurchase plan authorized.

+ References

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