Correction of Immaterial Errors in Prior Period Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Apr. 26, 2020	Apr. 28, 2019
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Selling, general and administrative	$ 34,600	$ 38,972
Product development and engineering	27,586	27,154
Total operating costs and expenses	64,993	69,108
Operating income	15,768	12,167
Income before taxes and equity in net losses of equity method investments	11,002	10,743
Benefit for income taxes	1,359	(2,416)
Net income before equity in net losses of equity method investments		13,159
Net income	$ 9,632	$ 12,748
Basic (in dollars per share)	$ 0.15	$ 0.19
Diluted (in dollars per share)	$ 0.15	$ 0.19
Comprehensive income	$ 8,626	$ 12,736
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Selling, general and administrative		38,377
Product development and engineering		27,099
Total operating costs and expenses		68,458
Operating income		12,817
Income before taxes and equity in net losses of equity method investments		11,393
Benefit for income taxes		(2,312)
Net income before equity in net losses of equity method investments		13,705
Net income		$ 13,294
Basic (in dollars per share)		$ 0.20
Diluted (in dollars per share)		$ 0.20
Comprehensive income		$ 13,282