Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenues:
Total revenues		$ 1,409,000	$ 1,071,000	$ 2,769,000	$ 2,117,000
Cost of revenues:
Total cost of revenues	[1]	329,000	233,000	628,000	456,000
Gross profit		1,080,000	838,000	2,141,000	1,661,000
Operating expenses:
Sales and marketing	[1]	557,000	426,000	1,081,000	867,000
Research and development	[1]	333,000	245,000	647,000	472,000
General and administrative	[1]	139,000	104,000	265,000	210,000
Total operating expenses	[1]	1,029,000	775,000	1,993,000	1,549,000
Income from operations		51,000	63,000	148,000	112,000
Interest expense		(7,000)	(8,000)	(14,000)	(17,000)
Other income, net		6,000	7,000	15,000	15,000
Income before income taxes		50,000	62,000	149,000	110,000
Provision for (benefit from) income taxes		(9,000)	21,000	8,000	21,000
Net income		$ 59,000	$ 40,766	$ 140,835	$ 88,997
Net income per share - basic (in dollars per share)		$ 0.30	$ 0.21	$ 0.71	$ 0.47
Net income per share - diluted (in dollars per share)		$ 0.29	$ 0.20	$ 0.70	$ 0.44
Weighted-average shares used to compute net income per share - basic (in shares)		197,815	191,319	197,216	190,731
Weighted-average shares used to compute net income per share - diluted (in shares)		202,273	201,453	202,348	200,843
Other comprehensive income:
Foreign currency translation adjustments		$ 14,000	$ 18,000	$ (17,000)	$ (2,000)
Unrealized gain (loss) on investments, net of tax		0	27,000	(7,000)	7,000
Other comprehensive income (loss)		14,000	45,000	(24,000)	5,000
Comprehensive income		73,000	86,000	117,000	94,000
Subscription
Revenues:
Total revenues		1,330,000	1,015,000	2,623,000	2,010,000
Cost of revenues:
Total cost of revenues	[1]	248,000	172,000	476,000	332,000
Professional services and other
Revenues:
Total revenues		79,000	56,000	146,000	107,000
Cost of revenues:
Total cost of revenues	[1]	$ 81,000	$ 61,000	$ 152,000	$ 124,000

[1] Includes stock-based compensation as follows:  Three Months Ended June 30,Six Months Ended June 30,2021202020212020Cost of revenues:Subscription$33 $25 $62 $46 Professional services and other15 13 28 25 Operating expenses:Sales and marketing99 79 192 149 Research and development98 70 186 129 General and administrative37 30 70 56