CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Revenues:
Products	$ 403,925	$ 373,204
Services	83,542	83,709
Total revenues	487,467	456,913
Cost of revenues:
Cost of products	180,958	154,883
Cost of services	36,677	37,014
Total cost of revenues (exclusive of acquired intangible assets amortization shown separately below)	217,635	191,897
Gross profit	269,832	265,016
Operating expenses:
Selling and administrative	90,505	84,792
Engineering and development	74,408	75,978
Acquired intangible assets amortization	7,698	7,952
Restructuring and other	(313)	2,511
Total operating expenses	172,298	171,233
Income from operations	97,534	93,783
Non-operating (income) expense:
Interest income	(5,981)	(3,520)
Interest expense	6,890	5,402
Other (income) expense, net	805	(115)
Income before income taxes	95,820	92,016
Income tax provision	8,846	6,795
Net income	$ 86,974	$ 85,221
Net income per common share:
Basic	$ 0.45	$ 0.43
Diluted	$ 0.43	$ 0.42
Weighted average common shares-basic	195,255	200,005
Weighted average common shares-diluted	203,484	201,936
Cash dividend declared per common share	$ 0.09	$ 0.07