CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Net sales	$ 163,084	$ 177,707	$ 291,138	$ 282,147
Cost of sales	87,952	98,578	162,394	158,699
Gross profit	75,132	79,129	128,744	123,448
Operating expenses:
Marketing and selling	33,706	33,096	63,011	57,789
Administrative management, finance and information systems	4,190	12,598	16,165	20,985
Research and development	5,442	5,591	10,973	10,852
Total operating expenses	43,338	51,285	90,149	89,626
Operating profit	31,794	27,844	38,595	33,822
Interest income	(484)	(317)	(1,139)	(857)
Interest expense	35	36	70	73
Other expense (income), net	3,866	(1,895)	2,698	255
Profit before income taxes	28,377	30,020	36,966	34,351
Income tax expense	7,990	8,097	10,149	8,907
Net income	$ 20,387	$ 21,923	$ 26,817	$ 25,444
Weighted average common shares - Basic:
Participating securities (shares)	25	26	23	32
Weighted average common shares - Dilutive (shares)	10,060	10,028	10,047	10,015
Class A
Weighted average common shares - Basic:
Weighted average common shares - Basic (shares)	8,823	8,790	8,812	8,771
Net income per common share - Basic:
Net income per common share - Basic (USD per share)	$ 2.05	$ 2.21	$ 2.70	$ 2.57
Net income per common share - Diluted:
Net income per common share - Diluted (USD per share)	$ 2.02	$ 2.18	$ 2.66	$ 2.53
Class B
Weighted average common shares - Basic:
Weighted average common shares - Basic (shares)	1,212	1,212	1,212	1,212
Net income per common share - Basic:
Net income per common share - Basic (USD per share)	$ 1.86	$ 2.01	$ 2.45	$ 2.33
Net income per common share - Diluted:
Net income per common share - Diluted (USD per share)	$ 2.02	$ 2.18	$ 2.66	$ 2.53