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Summary of Significant Accounting Policies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018	Jan. 01, 2017	Dec. 31, 2016
Property, Plant and Equipment
Cash and cash equivalents	$ 10,282,000	$ 37,678,000			$ 30,363,000
Impairments of long lived assets	0	0
Goodwill impairment	0	0
Impairment of finite lived intangible assets	0	0
Accrued warranty	2,057,000	8,682,000
Foreign currency transaction loss	(483,000)	804,000
Research and development expenses	$ 2,646,000	2,241,000
Retained Earnings
Property, Plant and Equipment
ASU adjustments				$ 6,769,000
ASU 2016-06
Property, Plant and Equipment
ASU adjustments			$ (305,000)
ASU 2016-06 \| Retained Earnings
Property, Plant and Equipment
ASU adjustments			$ (305,000)
Minimum
Property, Plant and Equipment
Finite lived intangible asset, useful life	4 years
Maximum
Property, Plant and Equipment
Finite lived intangible asset, useful life	25 years
Weighted Average
Property, Plant and Equipment
Finite lived intangible asset, useful life	15 years
Buildings \| Minimum
Property, Plant and Equipment
Property, plant and equipment useful life	5 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	5 years
Leasehold improvements \| Maximum
Property, Plant and Equipment
Property, plant and equipment useful life	20 years
Non Domestic
Property, Plant and Equipment
Cash and cash equivalents	$ 8,058,000	35,807,000
Bank term deposits	$ 16,000	$ 17,000