Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Revenues [Abstract]
Revenues	$ 750,895	$ 666,607	$ 2,215,208	$ 1,922,982
Costs and Expenses:
Marketing and sales	143,401	123,738	412,194	369,958
Research and development	289,105	250,934	845,324	743,423
General and administrative	42,990	35,928	123,275	105,161
Amortization of acquired intangibles	5,000	4,438	14,661	13,234
Restructuring and other charges (credits)	(222)	13	(968)	(1,329)
Total costs and expenses	556,861	497,335	1,631,799	1,462,409
Income from operations	194,034	169,272	583,409	460,573
Interest expense	(4,196)	(5,325)	(12,729)	(15,876)
Other income (expenses), net	(1,143)	1,766	3,701	1,862
Income before provision for income taxes	188,695	165,713	574,381	446,559
Provision for income taxes	12,388	4,083	55,005	29,653
Net income	$ 176,307	$ 161,630	$ 519,376	$ 416,906
Net income per share - basic (usd per share)	$ 0.65	$ 0.59	$ 1.90	$ 1.52
Net Income per share - diluted (usd per share)	$ 0.63	$ 0.58	$ 1.86	$ 1.49
Weighted average common shares outstanding - basic (in shares)	273,194	273,996	273,636	273,633
Weighted average common shares outstanding - diluted (in shares)	278,311	280,024	279,046	279,455
Product and maintenance [Member]
Revenues [Abstract]
Revenues	$ 706,160	$ 630,329	$ 2,093,098	$ 1,813,384
Costs and Expenses:
Cost of sales	54,185	64,800	174,933	175,915
Service [Member]
Revenues [Abstract]
Revenues	44,735	36,278	122,110	109,598
Costs and Expenses:
Cost of sales	$ 22,402	$ 17,484	$ 62,380	$ 56,047