Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenue	$ 794,715	$ 705,074	$ 1,559,017	$ 1,411,582
Costs and operating expenses:
Cost of revenue (exclusive of amortization of acquired intangible assets shown below)	276,804	242,193	545,386	482,936
Research and development	64,090	61,439	135,314	127,580
Sales and marketing	123,469	135,106	247,255	261,382
General and administrative	129,709	120,116	257,070	242,951
Amortization of acquired intangible assets	10,381	9,648	20,815	19,247
Restructuring (benefit) charge	(167)	790	10,418	7,179
Total costs and operating expenses	604,286	569,292	1,216,258	1,141,275
Income from operations	190,429	135,782	342,759	270,307
Interest income	9,502	6,410	16,545	15,045
Interest expense	(17,249)	(8,446)	(34,454)	(20,562)
Other expense, net	(1,603)	(578)	(5,711)	(67)
Income before provision for income taxes	181,079	133,168	319,139	264,723
Provision for income taxes	(18,671)	(19,253)	(32,963)	(43,678)
Loss from equity method investment	(493)	0	(1,115)	0
Net income	$ 161,915	$ 113,915	$ 285,061	$ 221,045
Net income per share:
Basic (in dollars per share)	$ 1.00	$ 0.70	$ 1.76	$ 1.35
Diluted (in dollars per share)	$ 0.98	$ 0.69	$ 1.74	$ 1.34
Shares used in per share calculations:
Basic (in shares)	162,413	163,407	162,203	163,322
Diluted (in shares)	164,768	165,019	164,226	164,903