CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 30, 2018	Mar. 31, 2017	Mar. 30, 2018	Mar. 31, 2017
Net sales	$ 165,778	$ 149,807	$ 282,357	$ 243,536
Cost of sales	91,583	84,894	159,351	142,058
Gross profit	74,195	64,913	123,006	101,478
Operating expenses:
Marketing and selling	31,594	28,796	58,089	49,618
Administrative management, finance and information systems	11,235	11,001	21,642	21,562
Research and development	5,364	4,658	10,236	9,368
Total operating expenses	48,193	44,455	89,967	80,548
Operating profit	26,002	20,458	33,039	20,930
Interest income	(119)	(9)	(321)	(32)
Interest expense	43	124	115	610
Other (income) expense, net	(3,367)	(1,494)	(4,524)	(1,440)
Profit before income taxes	29,445	21,837	37,769	21,792
Income tax expense	7,825	7,878	15,914	3,777
Net income	$ 21,620	$ 13,959	$ 21,855	$ 18,015
Weighted avage common shares - Basic:
Participating securities (shares)	44	19	46	21
Weighted average common shares - Dilutive (shares)	9,993	9,915	9,979	9,892
Class A
Weighted avage common shares - Basic:
Weighted average common shares - Basic (shares)	8,737	8,684	8,721	8,659
Net income per common share - Basic:
Net income per common share - Basic (USD per share)	$ 2.19	$ 1.41	$ 2.21	$ 1.83
Net income per common share - Diluted:
Net income per common share - Diluted (USD per share)	2.15	1.39	2.18	1.80
Dividends declared per common share:
Dividends declared per common share (USD per share)	$ 0.12	$ 0.09	$ 0.22	$ 0.18
Class B
Weighted avage 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)	$ 1.99	$ 1.28	$ 2.01	$ 1.66
Net income per common share - Diluted:
Net income per common share - Diluted (USD per share)	2.15	1.39	2.18	1.80
Dividends declared per common share:
Dividends declared per common share (USD per share)	$ 0.11	$ 0.08	$ 0.2	$ 0.16