Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2019
Property, Plant and Equipment
Cash and cash equivalents	$ 14,178,000	$ 10,282,000
Impairments of long lived assets	0	0
Goodwill impairment	0	0
Impairment of finite lived intangible assets	0	0
Accrued warranty	1,222,000	2,057,000
Foreign currency transaction loss	202,000	(483,000)
Research and development expenses	2,614,000	2,646,000
Accumulated other comprehensive loss	$ (20,183,000)	(22,191,000)
Accounting Standards Update 2018-02 | Reclassified
Property, Plant and Equipment
Accumulated other comprehensive loss			$ 633,000
Buildings | Minimum
Property, Plant and Equipment
Property, plant and equipment useful life	7 years
Buildings | Maximum
Property, Plant and Equipment
Property, plant and equipment useful life	40 years
Machinery and equipment | Minimum
Property, Plant and Equipment
Property, plant and equipment useful life	2 years
Machinery and equipment | Maximum
Property, Plant and Equipment
Property, plant and equipment useful life	13 years
Leasehold improvements | Minimum
Property, Plant and Equipment
Property, plant and equipment useful life	6 years
Leasehold improvements | Maximum
Property, Plant and Equipment
Property, plant and equipment useful life	10 years
Non Domestic
Property, Plant and Equipment
Cash and cash equivalents	$ 13,660,000	8,058,000
Bank term deposits	$ 17,000	$ 16,000