Summary of Business and Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended					0 Months Ended	12 Months Ended
	Jan. 31, 2014	Jan. 31, 2014 Segment	Jan. 31, 2013	Jan. 31, 2012	Jan. 31, 2014 Money market funds [Member]	Jan. 31, 2013 Money market funds [Member]	Oct. 21, 2013 Class A common stock [Member]	Jan. 31, 2014 Class A common stock [Member]	Jan. 31, 2014 2013 Employee Stock Purchase Plan [Member]	Jan. 31, 2014 Software [Member]	Jan. 31, 2014 Accounts receivable [Member]	Jan. 31, 2014 Revenues [Member]	Jan. 31, 2014 Minimum [Member]	Jan. 31, 2014 Minimum [Member] Equipment and computers [Member]	Jan. 31, 2014 Minimum [Member] Furniture and fixtures [Member]	Jan. 31, 2014 Minimum [Member] Equipment [Member]	Jan. 31, 2014 Maximum [Member]	Jan. 31, 2014 Maximum [Member] Equipment and computers [Member]	Jan. 31, 2014 Maximum [Member] Furniture and fixtures [Member]	Jan. 31, 2014 Maximum [Member] Equipment [Member]
Summary Of Business And Accounting Policies [Line Items]
Shares issued in initial public offering							15,001,750
Offering price per share							$ 20.00
Shares sold and issued by the Company							11,676,750
Shares issued to underwriters under over-allotment option							1,956,750
Shares sold by certain selling shareholders							3,325,000
Net proceeds from initial public offering, after deducting underwriting discounts and commissions							$ 217,200,000	$ 214,500,000
Initial public offering costs							3,000,000
Offering costs not yet paid								300,000
Number of operating segment		1
Customer payment period													30 days				60 days
Entity wide net revenue major customer percentage minimum											10.00%	10.00%
Highly liquid investments maturity		3 months
Cash equivalents in money market accounts					170,200,000	7,600,000
Estimated useful lives														3 years	3 years	3 years		5 years	5 years	5 years
Estimated economic lives										2 years 4 months 24 days			2 years 3 months 18 days				5 years 4 months 24 days
Impairment of goodwill	0
Impairment recognized for long-lived assets		0	0	0
Share-based compensation cost recognition vesting service period		5 years											4 years				5 years
Recognition period of stock-based compensation expenses on straight-line basis									7 months
Sales commission expense		11,800,000	6,600,000	4,300,000
Advertising expense		$ 200,000