Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 25, 2017	Mar. 26, 2016
Net sales	$ 81,097	$ 65,778
Cost and expenses:
Cost of sales	48,841	46,496
Research and development	9,776	7,680
Selling, general and administrative	14,460	13,114
	73,077	67,290
Income (loss) from operations	8,020	(1,512)
Interest and other, net	101	43
Income (loss) from continuing operations before taxes	8,121	(1,469)
Income tax provision	1,358	222
Income (loss) from continuing operations	6,763	(1,691)
Income from discontinued operations
Net income (loss)	$ 6,763	$ (1,691)
Basic:
Income (loss) from continuing operations (in dollars per share)	$ 0.25	$ (0.06)
Income from discontinued operations (in dollars per share)
Net income (loss) (in dollars per share)	0.25	(0.06)
Diluted:
Income (loss) from continuing operations (in dollars per share)	0.24	(0.06)
Income from discontinued operations (in dollars per share)
Net income (loss) (in dollars per share)	$ 0.24	$ (0.06)
Weighted average shares used in computing income (loss) per share:
Basic (in shares)	26,978	26,317
Diluted (in shares)	28,252	26,317
Cash dividends declared per share (in dollars per share)	$ 0.06	$ 0.06