Quarterly Financial Data (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 6,318,000	$ 4,654,000	$ 5,842,000	$ 5,140,000	$ 8,117,000	$ 9,455,000	$ 8,245,000	$ 7,419,000	$ 21,954,000	$ 33,236,000
Gross profit	1,596,000	926,000	1,465,000	774,000	3,247,000	3,563,000	3,005,000	2,746,000	4,761,000	12,561,000
Net income (loss)	$ (2,459,000)	$ (978,000)	$ (488,000)	$ (1,096,000)	$ 406,000	$ 645,000	$ 184,000	$ 164,000	$ (5,021,000)	$ 1,399,000
Net income (loss) per share:
Basic	$ (0.21)	$ (0.08)	$ (0.04)	$ (0.09)	$ 0.04	$ 0.05	$ 0.02	$ 0.01	$ (0.42)	$ 0.12
Diluted	$ (0.21)	$ (0.08)	$ (0.04)	$ (0.09)	$ 0.04	$ 0.05	$ 0.02	$ 0.01	$ (0.42)	$ 0.12