Description of offering period.

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Number of unvested shares to be repurchased.

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Restricted stock weighted average grant date fair value.

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- Definition

Aggregate number of common shares reserved for future issuance.

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-SubTopic 10
-Section S99
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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.

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

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Unrecognized cost of unvested options awarded to employees as compensation.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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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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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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-Name Accounting Standards Codification
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- Definition

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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- Definition

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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- Definition

The increase or decrease in number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding, including vested options.

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- Definition

Maximum number of shares that may be issued in accordance with the plan as a proportion of outstanding capital stock.

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No definition available.

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- Definition

Percentage of vesting of share-based compensation awards.

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- Definition

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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- Definition

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

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No definition available.

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- Definition

Number of shares of stock issued during the period pursuant to acquisitions.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Stock-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Jan. 31, 2015	Jan. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Description of offering period excluding initial offering period	the offering period resets and the new lower price becomes the new offering price for a new 24 month offering period
Unvested shares subject to repurchase	0
Aggregate intrinsic value of exercised options	$ 11,900,000	$ 5,300,000
Aggregate estimated fair value of stock options granted to employees vested	$ 5,700,000	$ 6,100,000
Weighted-average grant date fair value of options granted to employees	$ 5.25	$ 7.7
Unrecognized stock-based compensation expense related to stock option	$ 23,600,000
Remaining weighted-average period	2 years 3 months 26 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period	2 years 11 months 19 days
Unrecognized stock-based compensation expense	$ 134,200,000
Unvested shares outstanding	10,129,260			8,204,968
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period	1 year 18 days
Unrecognized stock-based compensation expense	$ 37,000
Unvested shares outstanding	19,430			30,607
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
2015 Equity Incentive Plan \| Class A Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance	17,960,272		12,200,000
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance	3,138,536
Percentage of eligible compensation allowed to employees to purchase shares at a discount	15.00%
Description of offering period excluding initial offering period	Except for the initial offering period, the 2015 ESPP provides for 24-month offering periods beginning March 16 and September 16 of each year, and each offering period will consist of four six-month purchase periods.
Purchase price of common stock, percentage	85.00%
Unrecognized stock-based compensation expense	$ 16,000,000
Dividend yield	0.00%	0.00%
2015 Employee Stock Purchase Plan \| Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period	1 year 4 months 28 days
Unrecognized stock-based compensation expense	$ 1,800,000
Issuance of common stock in connection with acquisition (in shares)			344,667
Weighted average grant date fair value, 2015 acquisition			$ 12.96
Unvested shares outstanding	267,717
2015 Employee Stock Purchase Plan \| Class A Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance			2,500,000
Shares common stock, increase	2,500,000
Shares common stock, outstanding shares of capital stock	1.00%
Other Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance	52,671
Remaining weighted-average period	1 year 2 months 1 day
Unrecognized stock-based compensation expense	$ 600,000
Vesting Commencement Per Year \| 2015 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and restricted stock units vesting percentage	25.00%
Vesting Commencement Per Month
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and restricted stock units vesting percentage	2.08%
Vesting Commencement Per Quarter
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options and restricted stock units vesting percentage	6.25%