Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jul. 31, 2020		Jul. 31, 2019		Jul. 31, 2020	Jul. 31, 2019
Revenues:
Total revenues	$ 353,683		$ 266,900		$ 690,789	$ 511,652
Cost of revenues:
Total cost of revenues	97,204	[1]	70,218	[1]	192,084	135,721
Gross profit	256,479		196,682		498,705	375,931
Operating expenses:
Research and development	70,053	[1]	51,146	[1]	132,290	96,119
Sales and marketing	59,172	[1]	45,821	[1]	114,927	85,438
General and administrative	37,173	[1]	25,859	[1]	73,842	49,349
Total operating expenses	166,398	[1]	122,826	[1]	321,059	230,906
Operating income	90,081		73,856		177,646	145,025
Other income, net	2,881		7,332		6,295	13,493
Income before income taxes	92,962		81,188		183,941	158,518
Provision for (benefit from) income taxes	(589)		1,946		3,820	5,827
Net income	93,551		79,242		180,121	152,691
Net income, basic and diluted	$ 93,551		$ 79,242		$ 180,121	$ 152,691
Net income per share:
Basic (in usd per share)	$ 0.62		$ 0.54		$ 1.20	$ 1.04
Diluted (in usd per share)	$ 0.58		$ 0.50		$ 1.12	$ 0.96
Weighted-average shares used to compute net income per share:
Basic (in shares)	150,413		147,510		149,982	147,116
Diluted (in shares)	160,840		158,675		160,309	158,339
Other comprehensive income:
Net change in unrealized gain on available-for-sale investments	$ 1,131		$ 461		$ 2,428	$ 1,423
Net change in cumulative foreign currency translation loss	2,893		(1,742)		3,282	(2,444)
Comprehensive income	97,575		77,961		185,831	151,670
Subscription services
Revenues:
Total revenues	283,502		217,312		553,737	415,427
Cost of revenues:
Total cost of revenues	43,400	[1]	31,480	[1]	86,612	61,858
Professional services and other
Revenues:
Total revenues	70,181		49,588		137,052	96,225
Cost of revenues:
Total cost of revenues	$ 53,804	[1]	$ 38,738	[1]	$ 105,472	$ 73,863

[1] Includes stock-based compensation as follows: Cost of revenues:Cost of subscription services$1,532 $583 $2,551 $968 Cost of professional services and other7,318 4,458 12,392 7,436 Research and development16,437 9,509 27,838 15,833 Sales and marketing11,186 7,177 19,378 12,325 General and administrative12,893 6,643 24,114 12,564 Total stock-based compensation$49,366 $28,370 $86,273 $49,126