Selected Quarterly Financial Data - Summary of Quarterly Financial Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2014		Jan. 31, 2013		Jan. 31, 2012
Revenues:
Subscription services	$ 45,686	$ 38,935	$ 34,063	$ 27,937	$ 24,109	$ 19,969	$ 15,772	$ 13,430	$ 146,621		$ 73,280		$ 32,613
Professional services and other	17,117	16,044	15,518	14,851	15,679	15,827	13,683	11,079	63,530		56,268		28,649
Total revenues	62,803	54,979	49,581	42,788	39,788	35,796	29,455	24,509	210,151		129,548		61,262
Cost of revenues:
Cost of subscription services	11,790	9,511	7,948	6,950	5,943	5,160	4,100	3,649	36,199	[1]	18,852	[1]	8,768	[1]
Cost of professional services and other	12,568	11,881	11,195	10,759	10,818	10,696	8,950	7,700	46,403	[1]	38,164	[1]	20,288	[1]
Total cost of revenues	24,358	21,392	19,143	17,709	16,761	15,856	13,050	11,349	82,602	[1]	57,016	[1]	29,056	[1]
Gross profit	38,445	33,587	30,438	25,079	23,027	19,940	16,405	13,160	127,549		72,532		32,206
Operating expenses:
Research and development	7,858	6,585	6,357	5,527	4,692	3,605	3,286	3,055	26,327	[1]	14,638	[1]	7,750	[1]
Sales and marketing	12,768	11,467	9,610	7,662	6,186	5,316	4,190	3,798	41,507	[1]	19,490	[1]	12,279	[1]
General and administrative	6,511	5,550	4,633	3,717	2,787	2,235	1,807	1,542	20,411	[1]	8,371	[1]	5,539	[1]
Total operating expenses	27,137	23,602	20,600	16,906	13,665	11,156	9,283	8,395	88,245	[1]	42,499	[1]	25,568	[1]
Operating income	11,308	9,985	9,838	8,173	9,362	8,784	7,122	4,765	39,304		30,033		6,638
Other income (expense), net	(365)	125	(65)	(499)	(603)	74	(421)	10	(804)		(940)		15
Income before income taxes	10,943	10,110	9,773	7,674	8,759	8,858	6,701	4,775	38,500		29,093		6,653
Provision for income taxes	4,696	3,585	3,775	2,829	3,075	3,109	2,454	1,672	14,885		10,310		2,423
Net income	$ 6,247	$ 6,525	$ 5,998	$ 4,845	$ 5,684	$ 5,749	$ 4,247	$ 3,103	$ 23,615		$ 18,783		$ 4,230

[1] Includes stock-based compensation as follows: Cost of revenues: Cost of subscription services $ 118 $ 3 $ 1 Cost of professional services and other 902 120 63 Research and development 1,700 238 106 Sales and marketing 1,788 140 99 General and administrative 2,442 214 165 Total stock-based compensation $ 6,950 $ 715 $ 434