Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Revenues [Abstract]
Revenues	$ 576,742	$ 517,313
Costs and Expenses:
Marketing and sales	116,830	109,148
Research and development	228,210	224,185
General and administrative	30,102	33,299
Amortization of acquired intangibles	3,308	3,630
Restructuring and other credits	(689)	(1,991)
Total costs and expenses	448,346	431,480
Income from operations	128,396	85,833
Interest expense	5,391	6,975
Other income (expense), net	5,241	(689)
Income before provision for income taxes	128,246	78,169
Provision for income taxes	7,691	5,284
Net income	$ 120,555	$ 72,885
Net income per share – basic	$ 0.44	$ 0.27
Net income per share – diluted	$ 0.43	$ 0.26
Weighted average common shares outstanding – basic	273,066	273,773
Weighted average common shares outstanding – diluted	280,615	281,651
Product and maintenance [Member]
Revenues [Abstract]
Revenues	$ 543,518	$ 480,609
Costs and Expenses:
Cost of sales	50,522	41,730
Technology Service [Member]
Revenues [Abstract]
Revenues	33,224	36,704
Costs and Expenses:
Cost of sales	$ 20,063	$ 21,479