Stockholders' Equity - Additional Information (Detail) - USD ($)	8 Months Ended	12 Months Ended
	Jun. 15, 2014	Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award		18,549,702	20,233,620
Board of directors service term		3 years
Dividend declared		$ 0
Dividend paid		$ 0
Unvested shares subject to repurchase at an aggregate price		$ 100,000	$ 100,000
Employee service share based compensation early exercise of stock options			0
Weighted-average grant date fair value of options granted		$ 12.36	$ 13.87	$ 2.78
Unrecognized compensation cost, net of estimated forfeitures, related to unvested stock options granted		$ 31,400,000
Closing stock price		$ 24.10
Intrinsic value of options exercised		$ 49,600,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period of unvested stock		3 years 9 months 18 days
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period of unvested stock		3 years 2 months 12 days
Weighted average grant date fair value, RSUs granted		$ 26.59
Unrecognized compensation cost, net of estimated forfeitures, related to unvested RSUs		$ 56,900,000
Total intrinsic value, vested		$ 11,900,000
2007 Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award		0
2007 Stock Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation cost recognition vesting service period		9 years
2007 Stock Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation cost recognition vesting service period		4 years
2012 Equity Incentive Award Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award		0
2013 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award		0
Minimum incremental of issuance of common stock		13,750,000
Common shares outstanding percentage		5.00%
Effective date of plan		Oct. 15, 2013
Equity incentive plan		The number of shares available for issuance under the 2013 EIP automatically increases on the first business day of each of our fiscal years, commencing in 2014, by a number equal to the least of (a) 13.75 million shares, (b) 5% of the shares of all classes of our common stock outstanding on the last business day of the prior fiscal year, or (c) the number of shares determined by our board of directors.
2013 Equity Incentive Plan [Member] | Stock Options [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option exercisable period		10 years
Stock option vesting period		9 years
2013 Equity Incentive Plan [Member] | Stock Options [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting period		5 years
2013 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value, RSUs granted		$ 26.59
2013 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Minimum incremental of issuance of common stock		2,200,000
Common shares outstanding percentage		1.00%
Common stock reserve for future issuance		4,000,000
Employee stock purchase plan		The number of shares available for issuance under the ESPP automatically increases on the first business day of each of our fiscal years, commencing in 2014, by a number equal to the least of (a) 2.2 million shares, (b) 1% of the shares of all classes of our common stock outstanding on the last business day of the prior fiscal year or (c) the number of shares determined by our board of directors.
Common stock acquire at fair market value		85.00%
Common stock purchases through payroll deductions		15.00%
2007 Stock Plans [Member] | Stock Options [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option exercisable period		10 years
Stock option vesting period		5 years
2007 Stock Plans [Member] | Stock Options [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting period		4 years
2012 Stock Plan [Member] | Stock Options [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option exercisable period		10 years
Stock option vesting period		9 years
2012 Stock Plan [Member] | Stock Options [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting period		5 years
2012 and 2013 Equity Incentive Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation cost recognition vesting service period		9 years
2012 and 2013 Equity Incentive Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation cost recognition vesting service period		4 years
Class A common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares outstanding		87,359,026	64,729,479
Conversion of common stock outstanding		100.00%
Conversion of common stock		100.00%
Class A common stock [Member] | 2013 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock Available for issuance		12,656,864
Class A common stock [Member] | 2013 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock issued in ESPP offering period	350,059
Class B common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares outstanding		46,186,159	66,338,146
Common stock, shares unvested		56,666	195,833