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Discontinued Operations (Details) - USD ($)		3 Months Ended			6 Months Ended
Discontinued Operations (Details) - USD ($)	Jul. 10, 2019	Sep. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale			$ 396,000		$ 396,000		$ 485,000
Storage costs			0		68,000
Loss from discontinued operations			(9,000)	$ (74,000)	(19,000)	$ (99,000)
Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Severance costs			30,000		0
Fuel Conversion Segment \| Accrued Liabilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Accrued severance charges			$ 5,000		5,000		65,000
Sold \| Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale							$ 0
Held-for-sale \| Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Storage costs					$ 13
Scenario, Forecast \| Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Severance costs		$ 5,000
Subsequent Event \| Held-for-sale \| Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal consideration	$ 500,000
Commissions	$ 50