Condensed Consolidated Statements Of Income (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 26, 2020	Jul. 28, 2019	Jul. 26, 2020	Jul. 28, 2019
Income Statement [Abstract]
Net sales	$ 143,660	$ 137,146	$ 276,362	$ 268,500
Cost of sales	55,409	52,262	107,350	102,341
Gross profit	88,251	84,884	169,012	166,159
Operating costs and expenses:
Selling, general and administrative	38,255	43,325	72,855	82,297
Product development and engineering	29,220	25,882	56,806	53,036
Intangible amortization	2,020	3,908	4,860	9,051
Changes in the fair value of contingent earn-out obligations	0	0	(33)	(2,161)
Total operating costs and expenses	69,495	73,115	134,488	142,223
Operating income	18,756	11,769	34,524	23,936
Interest expense	(1,252)	(2,597)	(2,811)	(5,064)
Non-operating (expense) income, net	(176)	1,213	247	2,256
Investment impairments and credit loss reserves	(1,485)	0	(5,115)	0
Income before taxes and equity in net (losses) gains of equity method investments	15,843	10,385	26,845	21,128
(Benefit) provision for income taxes	(416)	8,361	943	5,945
Net income before equity in net (losses) gains of equity method investments	16,259	2,024	25,902	15,183
Equity in net (losses) gains of equity method investments	(137)	168	(148)	(243)
Net income	16,122	2,192	25,754	14,940
Net loss attributable to noncontrolling interest	(3)	0	(6)	0
Net income attributable to common stockholders	$ 16,125	$ 2,192	$ 25,760	$ 14,940
Earnings per share:
Basic (in dollars per share)	$ 0.25	$ 0.03	$ 0.39	$ 0.23
Diluted (in dollars per share)	$ 0.24	$ 0.03	$ 0.39	$ 0.22
Weighted-average number of shares used in computing earnings per share:
Basic (in shares)	65,084	66,519	65,337	66,312
Diluted (in shares)	66,004	67,746	66,099	67,814