Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 3,198,149	$ 2,893,617	$ 2,714,474
Costs and operating expenses:
Cost of revenue (exclusive of amortization of acquired intangible assets shown below)	1,132,672	987,624	953,485
Research and development	269,315	261,365	246,165
Sales and marketing	510,405	523,883	517,353
General and administrative	547,888	516,093	574,067
Amortization of acquired intangible assets	42,049	38,581	33,311
Restructuring charge	37,286	17,153	27,594
Total costs and operating expenses	2,539,615	2,344,699	2,351,975
Income from operations	658,534	548,918	362,499
Interest income	29,122	34,355	26,940
Interest expense	(69,120)	(49,364)	(43,202)
Other expense, net	(2,454)	(1,428)	(3,148)
Income before provision for income taxes	616,082	532,481	343,089
Provision for income taxes	(45,922)	(53,350)	(44,716)
Loss from equity method investment	(13,106)	(1,096)	0
Net income	$ 557,054	$ 478,035	$ 298,373
Net income per share:
Basic (in dollars per share)	$ 3.43	$ 2.94	$ 1.78
Diluted (in dollars per share)	$ 3.37	$ 2.90	$ 1.76
Shares used in per share calculations:
Basic (in shares)	162,490	162,706	167,312
Diluted (in shares)	165,213	164,573	169,188