Discontinued Operations (Notes)	12 Months Ended
Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	DISCONTINUED OPERATIONS During 2017, the Company has suspended all operations associated with the Fuel Conversion business segment. The components of the net assets of the Fuel Conversion discontinued operations as of December 31, 2017 are included in Assets held for sale on the Consolidated Balance Sheets totaling $485 which consists primarily of certain equipment. The components of the net assets of the Fuel Conversion discontinued operations as of December 31, 2016 are included in Assets held for sale on the Consolidated Balance Sheets totaling $2,058 which consisted of certain equipment of $402 and the Carbonite intangible asset of $1,656. The resulting amount in assets held for sale was determined using management's assumptions based on a plan of sale and we may not be able to realize as much value from the sale of the assets as we expect. In addition, accrued severance of $376 is included in the other accrued liabilities line of the Consolidated Balance Sheets as of December 31, 2017. The Fuel Conversion business segment had no other assets or liabilities associated with it. The activity of the Fuel Conversion discontinued operations consisted of Research and Development, severance, an impairment charge and other costs for the years ended December 31, 2017, 2016, and 2015 of $3,914, $2,800 and $2,826, respectively. The loss from discontinued operations in the Consolidated Statement of Operations for the year ended December 31, 2017 includes the severance charges associated with suspension of the Fuel Conversion business segment of $581. The loss from discontinued operations in the Consolidated Statement of Operations for the year ended December 31, 2017 includes an impairment charge related to the Carbonite intangible asset of $1,354 as a result of not being able to reach an agreement with a third-party to acquire or license the Carbonite technology. Absent a third-party agreement, management determined there was not adequate gross cash flows to support the carrying value of the asset and recorded the impairment charge during the fourth quarter of 2017. The Fuel Conversion business segment had no revenues associated with it. The Company expects to incur $581 of severance costs relating to the suspension of the Fuel Conversion business segment, of which $205 was paid in 2017, $311 will be paid in 2018 and $65 will be paid in 2019. The Company expects to incur storage fees and other disposal costs associated with certain property, plant and equipment and contractual termination payments or other miscellaneous expenses but an estimated amount or range of amounts has not yet been determined.

DISCONTINUED OPERATIONS

During 2017, the Company has suspended all operations associated with the Fuel Conversion business segment. The components of the net assets of the Fuel Conversion discontinued operations as of December 31, 2017 are included in Assets held for sale on the Consolidated Balance Sheets totaling $485 which consists primarily of certain equipment. The components of the net assets of the Fuel Conversion discontinued operations as of December 31, 2016 are included in Assets held for sale on the Consolidated Balance Sheets totaling $2,058 which consisted of certain equipment of $402 and the Carbonite intangible asset of $1,656. The resulting amount in assets held for sale was determined using management's assumptions based on a plan of sale and we may not be able to realize as much value from the sale of the assets as we expect. In addition, accrued severance of $376 is included in the other accrued liabilities line of the Consolidated Balance Sheets as of December 31, 2017. The Fuel Conversion business segment had no other assets or liabilities associated with it.

The activity of the Fuel Conversion discontinued operations consisted of Research and Development, severance, an impairment charge and other costs for the years ended December 31, 2017, 2016, and 2015 of $3,914, $2,800 and $2,826, respectively. The loss from discontinued operations in the Consolidated Statement of Operations for the year ended December 31, 2017 includes the severance charges associated with suspension of the Fuel Conversion business segment of $581. The loss from discontinued operations in the Consolidated Statement of Operations for the year ended December 31, 2017 includes an impairment charge related to the Carbonite intangible asset of $1,354 as a result of not being able to reach an agreement with a third-party to acquire or license the Carbonite technology. Absent a third-party agreement, management determined there was not adequate gross cash flows to support the carrying value of the asset and recorded the impairment charge during the fourth quarter of 2017. The Fuel Conversion business segment had no revenues associated with it.

The Company expects to incur $581 of severance costs relating to the suspension of the Fuel Conversion business segment, of which $205 was paid in 2017, $311 will be paid in 2018 and $65 will be paid in 2019. The Company expects to incur storage fees and other disposal costs associated with certain property, plant and equipment and contractual termination payments or other miscellaneous expenses but an estimated amount or range of amounts has not yet been determined.