Property, Plant and Equipment - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Depreciation and amortization expense	$ 1,268,000	$ 1,025,000
Depreciation	1,178,000	948,000
Amortization	90,000	77,000
Property, plant and equipment, Gross	32,050,000	30,062,000
Machinery, equipment and tooling
Property, Plant and Equipment [Line Items]
ROU assets	728,000	811,000
Property, plant and equipment, Gross	20,695,000	18,345,000
ATG
Property, Plant and Equipment [Line Items]
Construction in progress	331,000	$ 1,258,000
ATG | Construction in progress (CIP) machinery & equipment and self-constructed assets
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	280,000
ATG | Construction in progress (CIP) IT equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	32,000
ATG | Construction in progress Building improvement
Property, Plant and Equipment [Line Items]
Property, plant and equipment, Gross	$ 19,000