Stockholders' Equity - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended				12 Months Ended															12 Months Ended			12 Months Ended
	Jan. 31, 2014	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2014 Maximum [Member]	Jan. 31, 2014 Minimum [Member]	Jan. 31, 2014 Restricted Stock Units (RSUs) [Member]	Jan. 31, 2014 2007 Stock Plans [Member] Stock Option Activity [Member] Maximum [Member]	Jan. 31, 2014 2007 Stock Plans [Member] Stock Option Activity [Member] Minimum [Member]	Jan. 31, 2014 2012 Stock Plan [Member] Stock Option Activity [Member] Maximum [Member]	Jan. 31, 2014 2012 Stock Plan [Member] Stock Option Activity [Member] Minimum [Member]	Jan. 31, 2014 2013 Equity Incentive Plan [Member] Stock Option Activity [Member] Maximum [Member]	Jan. 31, 2014 2013 Equity Incentive Plan [Member] Stock Option Activity [Member] Minimum [Member]	Jan. 31, 2014 2013 EIP [Member]	Jan. 31, 2014 2013 Employee Stock Purchase Plan [Member]	Jan. 31, 2014 2007 Stock Plan [Member]	Jan. 31, 2014 2012 Equity Incentive Award Plan [Member]	Jan. 31, 2014 Class B common stock [Member]	Jan. 31, 2013 Class B common stock [Member]	Dec. 31, 2013 Class A common stock [Member]	Jan. 31, 2014 Class A common stock [Member]	Jan. 31, 2013 Class A common stock [Member]	Jan. 31, 2014 Class A common stock [Member] 2013 EIP [Member]
Class of Stock [Line Items]
Common stock, Shares Outstanding	0	0	24,843,851																109,746,795	0		15,044,750	0
Common stock, shares unvested			3,369,972																1,824,457
Stock option award	25,424,437	25,424,437	13,428,750	11,725,625	8,089,250										0		0	0
Common stock Available for issuance																								2,065,657
Common stock Available for issuance															13,750,000
Common shares outstanding percentage															5.00%	1.00%
Effective date of plan															Oct. 15, 2013
Common stock reserve for future issuance																4,000,000
Minimum incremental of issuance of common stock																2,200,000
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%
Share purchase under ESPP																0
Board of directors service term		3 years
Dividend declared	$ 0	$ 0
Dividend paid	$ 0
Conversion of common stock outstanding																					1
Conversion of common stock																					1
Unvested shares subject to repurchase at an aggregate price	500,000	500,000	800,000
Cash received for early exercise of options		200,000	400,000
Stock option exercisable period									10 years		10 years		10 years
Stock option vesting period									5 years	4 years	9 years	5 years	9 years	5 years
Weighted average grant-date fair value of options granted		$ 2.78	$ 0.71	$ 0.28
Unrecognized compensation cost, net of estimated forfeitures, related to unvested stock options granted	37,700,000	37,700,000
Weighted average period of unvested stock options		5 years 2 months 12 days
Closing stock price	$ 31.79	$ 31.79
Intrinsic value of options exercised		21,332,807	2,544,332	287,864
Weighted average grant date fair value, RSUs Granted								$ 36.57
Unrecognized compensation cost related to unvested restricted stock units								5,400,000
Weighted average period related to unvested restricted stock unit								3 years 10 months 24 days
Share-based compensation expense, net of forfeitures, is recognized over the requisite service periods of awards		5 years				5 years	4 years
Dividend paid		0
Stock-based compensation capitalized as internal-use software		$ 500,000	$ 300,000