Unaudited Consolidated Condensed Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 27, 2013	Oct. 28, 2012	Oct. 27, 2013	Oct. 28, 2012
Net sales	$ 141,026	$ 160,878	$ 468,443	$ 428,224
Cost of sales	57,615	64,085	187,037	201,569
Gross profit	83,411	96,793	281,406	226,655
Operating costs and expenses:
Selling, general and administrative	30,849	35,646	98,958	111,684
Product development and engineering	31,948	33,354	99,632	90,050
Intangible amortization and impairments	7,349	8,212	25,016	21,767
Total operating costs and expenses	70,146	77,212	223,606	223,501
Operating income	13,265	19,581	57,800	3,154
Interest expense	(1,818)	(4,172)	(16,462)	(10,208)
Interest income and other (expense), net	(259)	(1,071)	(1,264)	(696)
Income (loss) before taxes	11,188	14,338	40,074	(7,750)
Benefit for taxes	(1,265)	(2,252)	(6,268)	(36,571)
Net income	$ 12,453	$ 16,590	$ 46,342	$ 28,821
Earnings per share:
Basic (in dollars per share)	$ 0.18	$ 0.25	$ 0.69	$ 0.44
Diluted (in dollars per share)	$ 0.18	$ 0.25	$ 0.67	$ 0.43
Weighted average number of shares used in computing earnings per share:
Basic (in shares)	67,792	65,996	67,454	65,622
Diluted (in shares)	68,871	67,465	68,819	67,306