Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Revenues:
Subscription services		$ 75,280	$ 56,572	$ 144,174	$ 105,093
Professional services and other		22,827	19,092	43,856	37,292
Total revenues		98,107	75,664	188,030	142,385
Cost of revenues:
Cost of subscription services	[1]	16,819	13,346	32,692	25,386
Cost of professional services and other	[1]	16,654	14,790	32,766	28,700
Total cost of revenues	[1]	33,473	28,136	65,458	54,086
Gross profit		64,634	47,528	122,572	88,299
Operating expenses:
Research and development	[1]	15,255	9,787	28,212	18,779
Sales and marketing	[1]	18,057	13,810	33,553	26,624
General and administrative	[1]	8,969	7,146	17,529	13,554
Total operating expenses	[1]	42,281	30,743	79,294	58,957
Operating income		22,353	16,785	43,278	29,342
Other income (expense), net		(445)	(101)	318	(131)
Income before income taxes		21,908	16,684	43,596	29,211
Provision for income taxes		8,502	7,106	17,208	12,412
Net income		13,406	9,578	26,388	16,799
Net income attributable to Class A and Class B common stockholders, basic and diluted		$ 13,390	$ 9,490	$ 26,357	$ 16,643
Net income per share attributable to Class A and Class B common stockholders:
Basic		$ 0.10	$ 0.07	$ 0.20	$ 0.13
Diluted		$ 0.09	$ 0.07	$ 0.18	$ 0.12
Weighted-average shares used to compute net income per share attributable to Class A and Class B common stockholders:
Basic		131,799	127,314	131,455	125,632
Diluted		144,871	143,353	144,870	143,506
Other comprehensive income (loss):
Net change in unrealized losses on available-for-sale investments		$ (76)	$ (114)	$ (79)	$ (68)
Net change in cumulative foreign currency translation gain (loss)		41	(23)	33	(57)
Comprehensive income		$ 13,371	$ 9,441	$ 26,342	$ 16,674

[1] Includes stock-based compensation as follows:  Cost of revenues: Cost of subscription services$136 $54 $247 $107 Cost of professional services and other 973 580 1,715 1,162 Research and development 1,643 874 3,026 1,761 Sales and marketing 1,755 760 2,875 1,536 General and administrative 1,104 1,132 2,547 2,090 Total stock-based compensation$5,611 $3,400 $10,410 $6,656