Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Net sales:
Products	$ 163,585	$ 179,030	$ 327,644	$ 348,328
Service	60,604	57,925	117,361	114,892
Total net sales	224,189	236,955	445,005	463,220
Cost of sales:
Products	78,825	92,077	160,326	178,673
Service	33,259	35,027	67,303	68,371
Total cost of sales	112,084	127,104	227,629	247,044
Gross profit	112,105	109,851	217,376	216,176
Operating expenses:
Research and development	23,128	26,221	46,450	51,866
Selling, general and administrative	43,093	50,587	88,915	99,050
Restructuring, reorganization, relocation and severance	(21)	2,228	(142)	3,559
Total operating expenses	66,200	79,036	135,223	154,475
Operating income	45,905	30,815	82,153	61,701
Other expense:
Interest income	254	221	465	373
Interest expense	(140)	(173)	(234)	(272)
Other, net	(704)	(854)	(1,788)	(1,177)
Total other expense, net	(590)	(806)	(1,557)	(1,076)
Income before income taxes	45,315	30,009	80,596	60,625
Income tax expense	7,983	5,061	15,252	10,599
Net income	$ 37,332	$ 24,948	$ 65,344	$ 50,026
Basic net income per share	$ 0.90	$ 0.59	$ 1.57	$ 1.19
Diluted net income per share	0.89	0.59	1.55	1.17
Cash dividends declared per share	$ 0.3	$ 0.25	$ 0.55	$ 0.37
Shares used in per share calculations:
Basic (in shares)	41,629	42,080	41,711	42,135
Diluted (in shares)	42,044	42,627	42,142	42,701