Condensed Consolidated Income Statements (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
Revenue:
Product and maintenance	$ 443,847	$ 419,963	$ 895,254	$ 831,707
Services	35,154	33,058	60,658	69,176
Total revenue	479,001	453,021	955,912	900,883
Costs and Expenses:
Cost of product and maintenance	38,829	42,960	82,546	87,141
Cost of services	22,003	18,823	40,078	36,696
Marketing and sales	103,897	101,110	207,244	200,310
Research and development	195,901	182,371	394,187	362,277
General and administrative	32,774	36,388	64,590	64,688
Amortization of acquired intangibles	3,836	4,537	7,692	10,317
Restructuring and other charges (credits)	(929)	(74)	(2,717)	14,512
Total costs and expenses	396,311	386,115	793,620	775,941
Income from operations	82,690	66,906	162,292	124,942
Interest expense	(6,248)	(5,896)	(12,727)	(11,253)
Other income, net	924	2,842	1,983	7,605
Income before provision for income taxes	77,366	63,852	151,548	121,294
Provision for income taxes	8,239	14,517	14,162	21,397
Net income	$ 69,127	$ 49,335	$ 137,386	$ 99,897
Net income per share - basic (in usd per share)	$ 0.25	$ 0.17	$ 0.51	$ 0.34
Net income per share - diluted (in usd per share)	$ 0.25	$ 0.17	$ 0.49	$ 0.33
Weighted average common shares outstanding - basic (in shares)	271,887	288,191	271,030	292,403
Weighted average common shares outstanding - diluted (in shares)	279,526	295,201	278,631	299,318