Summary of Business and Significant Accounting Policies - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended			0 Months Ended
	Jan. 31, 2015	Jan. 31, 2015 Segment	Jan. 31, 2014	Jan. 31, 2013	Mar. 31, 2014	Oct. 21, 2013
Summary Of Business And Accounting Policies [Line Items]
Number of operating segment		1
Highly liquid investments maturity		3 months
Impairment of goodwill	$ 0
Impairment recognized for long-lived assets		0	0	0
Sales commission expense		13,200,000	11,800,000	6,600,000
Advertising expense		100,000	200,000
2013 Employee Stock Purchase Plan [Member]
Summary Of Business And Accounting Policies [Line Items]
Recognition period of stock-based compensation expenses on straight-line basis		7 months
Building [Member]
Summary Of Business And Accounting Policies [Line Items]
Estimated useful lives		30 years
Internal-Use Software [Member]
Summary Of Business And Accounting Policies [Line Items]
Estimated economic lives		3 years
Customer Concentration Risk
Summary Of Business And Accounting Policies [Line Items]
Approximate sales percentage from largest customers		54.00%	56.00%	54.00%
Minimum [Member]
Summary Of Business And Accounting Policies [Line Items]
Customer payment period		30 days
Estimated economic lives		1 year 3 months 18 days
Minimum [Member] | 2007 Stock Plan [Member]
Summary Of Business And Accounting Policies [Line Items]
Share-based compensation cost recognition vesting service period		4 years
Minimum [Member] | Property and equipment [Member]
Summary Of Business And Accounting Policies [Line Items]
Estimated useful lives		3 years
Maximum [Member]
Summary Of Business And Accounting Policies [Line Items]
Customer payment period		60 days
Estimated economic lives		4 years 3 months 18 days
Maximum [Member] | 2007 Stock Plan [Member]
Summary Of Business And Accounting Policies [Line Items]
Share-based compensation cost recognition vesting service period		5 years
Maximum [Member] | Property and equipment [Member]
Summary Of Business And Accounting Policies [Line Items]
Estimated useful lives		5 years
Class A common stock [Member]
Summary Of Business And Accounting Policies [Line Items]
Shares issued in initial public offering						15,001,750
Offering price per share					$ 26.35	$ 20.00
Initial public/Follow-on offering, net of issuance costs, shares					1,390,000	11,676,750
Shares issued to underwriters under over-allotment option					1,800,000	1,956,750
Shares sold by other selling shareholders					12,410,000	3,325,000
Net proceeds from initial public offering, after deducting underwriting discounts and commissions					$ 34,500,000	$ 214,200,000
Shares issued in follow-on offering					13,800,000