Stock-Based Compensation - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014	Jan. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Liabilities related to early exercises of stock options	$ 58,000		$ 58,000		$ 286,000
Unvested shares subject to repurchase	45,624		45,624		113,541
Aggregate intrinsic value of exercised options			$ 11,300,000	$ 14,300,000
Aggregate estimated fair value of stock options granted to employees vested			$ 9,800,000	$ 6,600,000
Weighted-average grant date fair value of options granted to employees			$ 7.56	$ 8.29
Unrecognized stock-based compensation expense related to stock option	$ 36,800,000		$ 36,800,000
Remaining weighted-average period			2 years 7 months 17 days
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period			3 years 3 months 29 days
Unrecognized stock-based compensation expense	112,400,000		$ 112,400,000
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period			1 year 4 months 13 days
Unrecognized stock-based compensation expense	$ 499,000		$ 499,000
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	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	15,006,222		15,006,222
2015 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance	3,696,550		3,696,550
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.
Description of initial offering period			The initial offering period began January 23, 2015, and will end on March 15, 2017.
Purchase price of common stock, percentage			85.00%
Unrecognized stock-based compensation expense	$ 10,800,000		$ 10,800,000
2015 Employee Stock Purchase Plan | Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Remaining weighted-average period			2 years 26 days
Unrecognized stock-based compensation expense	$ 2,900,000		$ 2,900,000
Shares issued in connection with fiscal 2015 acquisitions					344,667
Restricted shares outstanding	342,187		342,187
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
Other Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares common stock reserved for issuance	92,107		92,107
Remaining weighted-average period			1 year 10 months 17 days
Unrecognized stock-based compensation expense	$ 1,000,000		$ 1,000,000
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%