Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Oct. 01, 2011	Oct. 02, 2010	Oct. 01, 2011	Oct. 02, 2010
Product sales	$ 321,348	$ 282,934	$ 940,834	$ 811,401
Service sales	133,186	118,104	388,930	348,392
Total net sales	454,534	401,038	1,329,764	1,159,793
Cost of product sales	124,228	113,345	361,409	317,640
Cost of service sales	56,090	49,640	164,841	146,410
Total cost of sales	180,318	162,985	526,250	464,050
Gross profit	274,216	238,053	803,514	695,743
Selling and administrative expenses	121,211	111,306	363,774	324,938
Research and development expenses	23,372	20,524	68,640	61,407
Purchased intangibles amortization	2,369	2,408	7,374	7,642
Operating income	127,264	103,815	363,726	301,756
Interest expense	(6,159)	(3,810)	(15,294)	(10,045)
Interest income	613	516	2,139	1,293
Income from operations before income taxes	121,718	100,521	350,571	293,004
Provision for income taxes	20,461	5,802	54,750	37,845
Net income	$ 101,257	$ 94,719	$ 295,821	$ 255,159
Net income per basic common share	$ 1.12	$ 1.03	$ 3.24	$ 2.75
Weighted-average number of basic common shares	90,688	91,714	91,334	92,647
Net income per diluted common share	$ 1.10	$ 1.02	$ 3.18	$ 2.71
Weighted-average number of diluted common shares and equivalents	92,060	93,286	92,898	94,271