CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) [Abstract]
Net sales	$ 60,860,852	$ 58,044,743	$ 120,305,849	$ 94,088,038
Cost of products sold	(45,807,496)	(42,530,749)	(90,531,018)	(69,829,465)
Gross margin	15,053,356	15,513,994	29,774,831	24,258,573
Product development expenses	(1,581,719)	(1,683,309)	(3,084,258)	(2,313,720)
Selling and administrative expenses	(9,083,131)	(11,344,223)	(18,130,180)	(17,222,190)
Operating profit	4,388,506	2,486,462	8,560,393	4,722,663
Interest expense	(312,060)	(311,654)	(608,390)	(332,678)
Other income	225,769	36,112	444,500	55,765
Income before income taxes	4,302,215	2,210,920	8,396,503	4,445,750
Income taxes	1,043,738	744,518	2,037,831	1,462,207
Net income	$ 3,258,477	$ 1,466,402	$ 6,358,672	$ 2,983,543
Earnings per Share:
Basic (in dollars per share)	$ 0.52	$ 0.23	$ 1.02	$ 0.48
Diluted (in dollars per share)	0.52	0.23	1.01	0.47
Cash dividends per share: (in dollars per share)	$ 0.11	$ 0.11	$ 0.22	$ 0.22