Condensed Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 26, 2015	Jul. 27, 2014	Jul. 26, 2015	Jul. 27, 2014
Net sales	$ 125,712	$ 145,742	$ 255,800	$ 278,601
Cost of sales	50,136	57,521	101,824	112,296
Gross profit	75,576	88,221	153,976	166,305
Operating costs and expenses:
Selling, general and administrative	34,528	31,547	72,203	63,243
Product development and engineering	28,239	28,173	57,917	55,986
Intangible amortization	6,177	6,444	12,340	12,869
Restructuring charge	3,564	0	3,564	1,001
Total operating costs and expenses	72,508	66,164	146,024	133,099
Operating income	3,068	22,057	7,952	33,206
Interest expense, net	(1,900)	(1,588)	(3,734)	(2,975)
Non-operating expense, net	117	(345)	(376)	(623)
Income before taxes	1,285	20,124	3,842	29,608
Provision for taxes	1,598	2,226	4,297	3,843
Net (loss) income	$ (313)	$ 17,898	$ (455)	$ 25,765
(Loss) earnings per share:
Basic (in dollars per share)	$ 0.00	$ 0.27	$ (0.01)	$ 0.38
Diluted (in dollars per share)	$ 0.00	$ 0.26	$ (0.01)	$ 0.38
Weighted average number of shares used in computing earnings per share:
Basic (in shares)	65,920	67,208	66,319	67,254
Diluted (in shares)	65,920	67,850	66,319	67,888