Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Revenues:
Subscription services		$ 316,314	$ 233,063	$ 146,621
Professional services and other		92,907	80,159	63,530
Total revenues		409,221	313,222	210,151
Cost of revenues:
Cost of subscription services	[1]	71,180	55,005	36,199
Cost of professional services and other	[1]	71,034	60,653	46,403
Total cost of revenues	[1]	142,214	115,658	82,602
Gross profit		267,007	197,564	127,549
Operating expenses:
Research and development	[1]	65,976	41,156	26,327
Sales and marketing	[1]	80,984	56,203	41,507
General and administrative	[1]	41,458	30,239	20,411
Total operating expenses	[1]	188,418	127,598	88,245
Operating income		78,589	69,966	39,304
Other income (expense), net		28	(2,780)	(804)
Income before income taxes		78,617	67,186	38,500
Provision for income taxes		24,157	26,803	14,885
Net income		54,460	40,383	23,615
Net income attributable to Class A and Class B common stockholders, basic and diluted		$ 54,413	$ 40,138	$ 10,405
Net income per share attributable to Class A and Class B common stockholders:
Basic		$ 0.41	$ 0.31	$ 0.20
Diluted		$ 0.38	$ 0.28	$ 0.15
Weighted-average shares used to compute net income per share attributable to Class A and Class B common stockholders:
Basic		132,020	127,713	51,725
Diluted		144,977	144,204	68,024
Other comprehensive income (loss):
Net change in unrealized gains (losses) on available-for-sale investments		$ (181)	$ 76	$ 10
Net change in cumulative foreign currency translation gain (loss)		327	(69)	4
Comprehensive income		$ 54,606	$ 40,390	$ 23,629

[1] (1)Includes stock-based compensation as follows:   Cost of revenues: Cost of subscription services$563 $273 $118 Cost of professional services and other 3,858 2,272 902 Research and development 7,249 3,844 1,700 Sales and marketing 6,861 3,221 1,788 General and administrative 5,727 4,715 2,442 Total stock-based compensation$24,258 $14,325 $6,950