Condensed Consolidated Statements Of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 28, 2018	Oct. 29, 2017	Oct. 28, 2018	Oct. 29, 2017
Net sales	$ 173,550	$ 150,304	$ 467,190	$ 447,233
Cost of sales	66,988	60,885	189,035	180,663
Gross profit	106,562	89,419	278,155	266,570
Operating costs and expenses:
Selling, general and administrative	39,587	36,568	114,522	109,820
Product development and engineering	27,147	27,631	81,425	81,046
Intangible amortization	6,480	7,453	19,921	20,414
Loss on disposition of business operations	0	0	0	375
Changes in the fair value of contingent earn-out obligations	(8,519)	188	(9,419)	188
Total operating costs and expenses	64,695	71,840	206,449	211,843
Operating income	41,867	17,579	71,706	54,727
Interest expense, net	(2,355)	(2,032)	(6,745)	(6,107)
Non-operating income, net	1,182	5,517	1,914	4,681
Investment impairments	(30,000)	(4,250)	(30,000)	(4,250)
Income before taxes and equity in net losses of equity method investments	10,694	16,814	36,875	49,051
Provision for taxes	(1,454)	3,272	(12,882)	11,124
Net income before equity in net losses of equity method investments	12,148	13,542	49,757	37,927
Equity in net gain (losses) of equity method investments	17	(204)	(41)	(204)
Net income	$ 12,165	$ 13,338	$ 49,716	$ 37,723
Earnings per share:
Basic (in dollars per share)	$ 0.18	$ 0.20	$ 0.75	$ 0.57
Diluted (in dollars per share)	$ 0.18	$ 0.20	$ 0.73	$ 0.56
Weighted average number of shares used in computing earnings per share:
Basic (in shares)	66,014	66,194	66,134	65,932
Diluted (in shares)	68,731	67,817	68,549	67,555