Condensed Consolidated Statements of Income - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 9,873,800	$ 6,482,000	$ 20,316,400	$ 14,337,900
Operating costs and expenses:
Cost of sales	5,606,800	3,766,900	11,229,000	7,624,000
Advertising	138,700	848,800	421,300	1,334,900
Selling	1,679,300	1,217,200	3,295,200	2,467,000
General and administrative	1,023,300	1,261,100	2,103,600	2,214,200
Total operating costs and expenses	8,448,100	7,094,000	17,049,100	13,640,100
Income (loss) from operations	1,425,700	(612,000)	3,267,300	697,800
Other income		5,400		11,600
Interest expense	(33,200)	(9,700)	(75,100)	(17,100)
Income (loss) before income taxes	1,392,500	(616,300)	3,192,200	692,300
Income tax (expense) benefit	(517,200)	269,700	(1,235,800)	(282,400)
Net income (loss)	$ 875,300	$ (346,600)	$ 1,956,400	$ 409,900
Net income (loss) per common share
Basic	$ 0.07	$ (0.03)	$ 0.17	$ 0.03
Diluted	$ 0.07	$ (0.03)	$ 0.16	$ 0.03
Weighted average shares outstanding:
Basic	11,859,927	11,733,734	11,818,143	11,722,240
Diluted	12,286,256	11,733,734	12,158,117	11,943,842