Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended			8 Months Ended
	Jan. 31, 2015	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2013	Jun. 15, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award	20,233,620	20,233,620	25,424,437
Board of directors service term		3 years
Dividend declared	$ 0	$ 0
Dividend paid	$ 0
Unvested shares subject to repurchase at an aggregate price	100,000	100,000	500,000
Cash received for early exercise of options			200,000
Employee Service Share Based Compensation Early Exercise Of Stock Options		0
Weighted-average grant date fair value of options granted		$ 13.87	$ 2.78	$ 0.71
Unrecognized compensation cost, net of estimated forfeitures, related to unvested stock options granted	34,900,000	34,900,000
Closing stock price	$ 28.76	$ 28.76
Intrinsic value of options exercised		104,689,345
Stock-based compensation capitalized as internal-use software		100,000	500,000
Unvested Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period of unvested stock		4 years 4 months 24 days
Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average grant date fair value, RSUs granted		$ 26.33
Unrecognized compensation cost, net of estimated forfeitures, related to unvested RSUs	$ 25,400,000	$ 25,400,000
Unvested Restricted Stock Units (RSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted average period of unvested stock		3 years 6 months
2007 Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award	0	0
2012 Equity Incentive Award Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award	0	0
2013 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option award	0	0
2013 Equity Incentive Plan [Member] | Stock Option Activity [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 Option Activity [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option vesting period		5 years
2013 EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Minimum incremental of issuance of common stock		13,750,000
Common shares outstanding percentage	5.00%	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 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%	1.00%
Common stock reserve for future issuance	4,000,000	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 Option Activity [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 Option Activity [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 Option Activity [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 Option Activity [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 expense, net of forfeitures, is recognized over the requisite service periods of awards		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 expense, net of forfeitures, is recognized over the requisite service periods of awards		4 years
Class A common stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares outstanding	64,729,479	64,729,479	15,044,750
Conversion of common stock outstanding		1
Conversion of common stock		1
Class A common stock [Member] | 2013 EIP [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock Available for issuance		8,149,581
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	66,338,146	66,338,146	109,746,795
Common stock, shares unvested	195,833	195,833	1,824,457