Consolidated Condensed Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Oct. 28, 2012	Oct. 30, 2011	Oct. 28, 2012	Oct. 30, 2011
Net sales	$ 160,878	$ 123,944	$ 428,224	$ 376,569
Cost of sales	64,085	50,537	201,569	150,588
Gross profit	96,793	73,407	226,655	225,981
Operating costs and expenses:
Selling, general and administrative	35,646	25,110	111,684	74,296
Product development and engineering	33,354	20,489	90,050	61,242
Intangible amortization and impairments	8,212	4,573	21,767	8,778
Total operating costs and expenses	77,212	50,172	223,501	144,316
Operating income	19,581	23,235	3,154	81,665
Interest expense	(4,172)	0	(10,208)	0
Interest income and other (expense) income, net	(1,071)	729	(696)	172
Income (loss) before taxes	14,338	23,964	(7,750)	81,837
(Benefit) provision for taxes	(2,252)	(3,015)	(36,571)	5,138
Net income	$ 16,590	$ 26,979	$ 28,821	$ 76,699
Earnings per share:
Basic (in dollars per share)	$ 0.25	$ 0.41	$ 0.44	$ 1.18
Diluted (in dollars per share)	$ 0.25	$ 0.40	$ 0.43	$ 1.14
Weighted average number of shares used in computing earnings per share:
Basic (shares)	65,996	65,440	65,622	65,180
Diluted (shares)	67,465	67,314	67,306	67,539