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Number of unvested shares to be repurchased.

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Stock options exercised liability recorded.

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Aggregate number of common shares reserved for future issuance.

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

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

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Percentage of vesting of share-based compensation awards.

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

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

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Stock-Based Compensation - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jan. 31, 2015	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Liabilities related to early exercises of stock options	$ 286,000	$ 11,000	$ 286,000
Unvested shares subject to repurchase	113,541	9,375	113,541
Aggregate intrinsic value of exercised options		$ 24,800,000	$ 27,500,000	$ 17,800,000
Aggregate estimated fair value of stock options granted to employees vested		$ 16,700,000	$ 16,400,000	$ 7,400,000
Weighted-average grant date fair value of options granted to employees		$ 6.72	$ 7.46	$ 4.75
Unrecognized stock-based compensation expense related to stock option		$ 29,200,000
Remaining weighted-average period		2 years 5 months 1 day
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period		3 years 15 days
Unrecognized stock-based compensation expense		$ 111,000,000
Unvested shares outstanding	4,939,709	8,204,968	4,939,709	225,300
Restricted Stock Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period		8 months 16 days
Unrecognized stock-based compensation expense		$ 123,000
Unvested shares outstanding	172,661	30,607	172,661	387,435
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield		0.00%	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	12,200,000	13,777,992	12,200,000
Shares common stock, increase	12,200,000
Shares common stock, outstanding shares of capital stock	5.00%
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance		2,761,742
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, our 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%
Remaining weighted-average period		1 year 7 months 13 days
Unrecognized stock-based compensation expense		$ 11,800,000
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 7 months 13 days
Unrecognized stock-based compensation expense		$ 2,200,000
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		71,037
Remaining weighted-average period		1 year 4 months 28 days
Unrecognized stock-based compensation expense		$ 700,000
Unvested shares outstanding		65,705
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%