Business Description and Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2020 USD ($) Y	Dec. 31, 2019 USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for doubtful accounts	$ 188,000	$ 337,000
Warranty reserve	382,000	420,000
Inventory reserve	$ 1,720,000	1,437,000
Warranty period	27 months
Income taxes paid, net of refund	$ 40,000	524,000
Interest paid	180,000	125,000
Impairment of long-lived assets	$ 0	$ 0
Concentration risk, benchmark description	No other customers of the ATG or CPG represented more than 10% of the Company's consolidated revenues in either of these years
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of years of customer requirements | Y	2
Number of year's supply | Y	1
Customer Concentration Risk | Advanced Technology Products | Sales Revenue | Two Customers
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Concentration Risk, Percentage	48.90%	48.90%
Concentration risk, benchmark description	more than 10%