Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue	$ 764,302	$ 706,508
Costs and operating expenses:
Cost of revenue (exclusive of amortization of acquired intangible assets shown below)	268,582	240,743
Research and development	71,224	66,141
Sales and marketing	123,786	126,276
General and administrative	127,361	122,835
Amortization of acquired intangible assets	10,434	9,599
Restructuring charge	10,585	6,389
Total costs and operating expenses	611,972	571,983
Income from operations	152,330	134,525
Interest income	7,043	8,635
Interest expense	(17,205)	(12,116)
Other (expense) income, net	(4,108)	511
Income before provision for income taxes	138,060	131,555
Provision for income taxes	(14,292)	(24,425)
Loss from equity method investment	(622)	0
Net income	$ 123,146	$ 107,130
Net income per share:
Basic (in dollars per share)	$ 0.76	$ 0.66
Diluted (in dollars per share)	$ 0.75	$ 0.65
Shares used in per share calculations:
Basic (in shares)	161,992	163,236
Diluted (in shares)	163,684	164,787