Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenues:
Total revenues		$ 788,926	$ 589,222
Cost of revenues:
Total cost of revenues	[1]	186,252	143,473
Gross profit		602,674	445,749
Operating expenses:
Sales and marketing	[1]	361,409	283,701
Research and development	[1]	172,522	117,268
General and administrative	[1]	84,456	65,063
Total operating expenses	[1]	618,387	466,032
Loss from operations		(15,713)	(20,283)
Interest expense		(8,168)	(17,064)
Interest income and other income (expense), net		12,425	29,987
Loss before income taxes		(11,456)	(7,360)
Benefit from income taxes		(9,911)	(17,982)
Net income (loss)		$ (1,545)	$ 10,622
Net income (loss) per share - basic (in dollars per share)		$ (0.01)	$ 0.06
Net income (loss) per share - diluted (in dollars per share)		$ (0.01)	$ 0.06
Weighted-average shares used to compute net income (loss) per share - basic (in shares)		182,061,579	175,482,833
Weighted-average shares used to compute net income (loss) per share - diluted (in shares)		182,061,579	190,249,786
Other comprehensive income (loss):
Foreign currency translation adjustments		$ 9,635	$ (8,435)
Unrealized gain (loss) on investments, net of tax		4,723	(3,068)
Other comprehensive income (loss), net of tax		14,358	(11,503)
Comprehensive income (loss)		12,813	(881)
Subscription
Revenues:
Total revenues		739,986	543,325
Cost of revenues:
Total cost of revenues	[1]	126,589	95,398
Professional services and other
Revenues:
Total revenues		48,940	45,897
Cost of revenues:
Total cost of revenues	[1]	$ 59,663	$ 48,075

[1] Includes stock-based compensation as follows:   Three Months Ended March 31,   2019   2018         Cost of revenues:       Subscription $ 16,022
  $ 11,291
Professional services and other 9,931
  7,561
Sales and marketing 62,130
  52,082
Research and development 43,582
  28,598
General and administrative 25,785
  21,809