Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 03, 2016	Mar. 29, 2015
Net sales:
Products	$ 162,278	$ 164,059
Service	66,366	56,757
Total net sales	228,644	220,816
Cost of sales:
Products	82,665	81,501
Service	38,707	34,044
Total cost of sales	121,372	115,545
Gross profit	107,272	105,271
Operating expenses:
Research and development	27,645	23,322
Selling, general and administrative	49,239	45,822
Restructuring and reorganization	(102)	(121)
Total operating expenses	76,782	69,023
Operating income	30,490	36,248
Other expense:
Interest income	184	211
Interest expense	(454)	(94)
Other, net	(821)	(1,084)
Total other expense, net	(1,091)	(967)
Income before income taxes	29,399	35,281
Income tax expense	6,497	7,269
Net income	$ 22,902	$ 28,012
Basic net income per share	$ 0.56	$ 0.67
Diluted net income per share	0.56	0.66
Cash dividends declared per share	$ 0.3	$ 0.25
Shares used in per share calculations:
Basic (in shares)	40,858	41,796
Diluted (in shares)	41,202	42,185