Correction of Immaterial Errors in Prior Period Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 26, 2020	Jul. 28, 2019	Jul. 26, 2020	Jul. 28, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Selling, general and administrative	$ 38,255	$ 43,325	$ 72,855	$ 82,297
Product development and engineering	29,220	25,882	56,806	53,036
Total operating costs and expenses	69,495	73,115	134,488	142,223
Operating income	18,756	11,769	34,524	23,936
Income before taxes and equity in net gains (losses) of equity method investments	15,843	10,385	26,845	21,128
Provision for income taxes	(416)	8,361	943	5,945
Net income before equity in net gains (losses) of equity method investments		2,024		15,183
Net income	$ 16,122	$ 2,192	$ 25,754	$ 14,940
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
Comprehensive income	$ 15,953	$ 2,070	$ 24,579	$ 14,806
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Selling, general and administrative		39,875		78,252
Product development and engineering		25,553		52,652
Total operating costs and expenses		69,336		137,794
Operating income		15,548		28,365
Income before taxes and equity in net gains (losses) of equity method investments		14,164		25,557
Provision for income taxes		8,966		6,654
Net income before equity in net gains (losses) of equity method investments		5,198		18,903
Net income		$ 5,366		$ 18,660
Basic (in dollars per share)		$ 0.08		$ 0.28
Diluted (in dollars per share)		$ 0.08		$ 0.28
Comprehensive income		$ 5,244		$ 18,526