Unaudited Consolidated Condensed Statements Of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jul. 28, 2013	Jul. 29, 2012	Jul. 28, 2013	Jul. 29, 2012
Net sales	$ 165,010	$ 150,704	$ 327,417	$ 267,346
Cost of sales	64,302	76,179	129,422	137,484
Gross profit	100,708	74,525	197,995	129,862
Operating costs and expenses:
Selling, general and administrative	33,315	31,220	68,109	76,038
Product development and engineering	33,125	32,613	67,684	56,696
Intangible amortization and impairments	9,811	7,977	17,667	13,555
Total operating costs and expenses	76,251	71,810	153,460	146,289
Operating income (loss)	24,457	2,715	44,535	(16,427)
Interest expense	(10,584)	(3,442)	(14,644)	(4,955)
Interest income and other (expense), net	(198)	(590)	(1,005)	(706)
Income (loss) before taxes	13,675	(1,317)	28,886	(22,088)
Benefit for taxes	(5,437)	(11,339)	(5,003)	(34,319)
Net income	$ 19,112	$ 10,022	$ 33,889	$ 12,231
Earnings per share:
Basic (in dollars per share)	$ 0.28	$ 0.15	$ 0.50	$ 0.19
Diluted (in dollars per share)	$ 0.28	$ 0.15	$ 0.49	$ 0.18
Weighted average number of shares used in computing earnings per share:
Basic (in shares)	67,614	65,587	67,285	65,435
Diluted (in shares)	69,090	67,165	68,812	67,207