Stockholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended			0 Months Ended	9 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2013	Oct. 31, 2012	Jan. 31, 2013	Oct. 21, 2013 Initial Public Offering [Member]	Oct. 31, 2013 Initial Public Offering [Member]	Oct. 21, 2013 Initial Public Offering [Member] Parent Company [Member]	Oct. 21, 2013 Initial Public Offering [Member] Underwriters Exercise Of Overallotment Option [Member]	Oct. 21, 2013 Initial Public Offering [Member] Stockholders' Equity, Total [Member]
Class of Stock [Line Items]
Common stock issued	0		0		24,843,851	15,001,750		11,676,750	1,956,750	3,325,000
Public offering price						$ 20.00
Proceeds from offering after deducting underwriting discount and commissions						$ 217,200,000
Offering expenses						2,900,000
Net cash proceeds	216,263,000		215,734,000				215,700,000
Estimated offering expenses accrued							1,400,000
Closing stock price	$ 38.91		$ 38.91
Intrinsic value of options exercised	4,100,000		15,042,513
Weighted-average grant date fair value of options granted	$ 6.98	$ 0.64	$ 2.72	$ 0.61
Unvested shares	2,244,353		2,244,353		3,369,972
Unvested shares subject to repurchase, aggregate price	600,000		600,000		800,000
Stock-based compensation capitalized as internal-use software	$ 100,000		$ 100,000