Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2018
Revenues:
Total revenues		$ 1,104,081	$ 862,210	$ 690,559
Cost of revenues:
Total cost of revenues	[1]	303,369	245,281	211,422
Gross profit		800,712	616,929	479,137
Operating expenses:
Research and development	[1]	209,895	158,783	132,017
Sales and marketing	[1]	190,331	148,867	128,781
General and administrative	[1]	114,267	86,413	60,410
Total operating expenses	[1]	514,493	394,063	321,208
Operating income		286,219	222,866	157,929
Other income, net		27,478	15,777	7,842
Income before income taxes		313,697	238,643	165,771
Provision for income taxes		12,579	8,811	14,594
Net income		301,118	229,832	151,177
Net income, basic and diluted		$ 301,118	$ 229,832	$ 151,177
Net income per share:
Basic		$ 2.04	$ 1.59	$ 1.08
Diluted		$ 1.90	$ 1.47	$ 0.98
Weighted-average shares used to compute net income per share:
Basic		147,796	144,244	140,311
Diluted		158,296	156,117	153,681
Other comprehensive income:
Net change in unrealized gain (losses) on available-for-sale investments		$ 2,388	$ 1,409	$ (1,598)
Net change in cumulative foreign currency translation gain (loss)		(2,857)	(2,081)	3,086
Comprehensive income		300,649	229,160	152,665
Subscription services
Revenues:
Total revenues		896,294	694,467	559,434
Cost of revenues:
Total cost of revenues	[1]	136,328	117,009	110,465
Professional services and other
Revenues:
Total revenues		207,787	167,743	131,125
Cost of revenues:
Total cost of revenues	[1]	$ 167,041	$ 128,272	$ 100,957

[1] Includes stock-based compensation as follows: Cost of revenues:           Cost of subscription services $ 2,638
  $ 1,553
  $ 1,448
Cost of professional services and other 17,518
  10,575
  8,476
Research and development 37,001
  22,138
  17,782
Sales and marketing 27,537
  18,381
  16,288
General and administrative 31,212
  23,778
  10,055
Total stock-based compensation $ 115,906
  $ 76,425
  $ 54,049