Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011
Condensed Consolidated Statements of Operations [Abstract]
Net sales	$ 59,404	$ 80,896	$ 112,700	$ 170,596
Cost and expenses:
Cost of sales	41,740	54,349	79,497	115,234
Research and development	8,688	9,284	17,058	18,367
Selling, general and administrative	11,041	11,434	21,917	23,524
Total cost and expenses	61,469	75,067	118,472	157,125
Income (loss) from operations	(2,065)	5,829	(5,772)	13,471
Interest and other, net	89	116	181	226
Income (loss) before income taxes	(1,976)	5,945	(5,591)	13,697
Income tax provision (benefit)	133	895	(258)	2,073
Net income (loss)	$ (2,109)	$ 5,050	$ (5,333)	$ 11,624
Income (loss) per share:
Basic	$ (0.09)	$ 0.21	$ (0.22)	$ 0.48
Diluted	$ (0.09)	$ 0.21	$ (0.22)	$ 0.47
Weighted average shares used in computing income (loss) per share:
Basic	24,432	24,103	24,392	24,060
Diluted	24,432	24,484	24,392	24,483
Cash dividends declared per share	$ 0.06	$ 0.06	$ 0.12	$ 0.12