Contingencies (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Charge for non-conformance issue	$ 1,150
Reversal of allowance for doubt	499,000	$ 1,082,000	$ 0
Accrued remediation contingency	0	0		$ 146,000
Change in warranty liability balance		0	0
Warranty liability balance	$ 159,000	$ 159,000	$ 159,000