Discontinued Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets held for sale	$ 485				$ 485					$ 485	$ 485
Accrued severance	65				376					65	376
Loss from discontinued operations	$ (4)	$ (10)	$ (74)	$ (25)	$ (1,676)	$ (239)	$ (1,269)	$ (730)		(113)	(3,914)	$ (2,800)
Intangible assets impairment										317	2,965	2,074
Payments for restructuring										326	618	$ 1,119
Carbonite
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Intangible assets impairment										56	1
Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Severance changes											581
Payments for restructuring										$ 311	$ 205
Scenario, Forecast | Fuel Conversion Segment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Payments for restructuring									$ 65