Goodwill and Other Intangibles	9 Months Ended
Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Other Intangibles Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. Fuel Tech has two reporting units for goodwill evaluation purposes: the FUEL CHEM^® technology segment and the APC technology segment. There is no goodwill associated with our APC segment. At both September 30, 2018 and December 31, 2017, our entire goodwill balance of $2,116 was allocated to the FUEL CHEM^® technology segment. Goodwill is allocated to each of our reporting units after considering the nature of the net assets giving rise to the goodwill and how each reporting unit would enjoy the benefits and synergies of the net assets acquired. There were no indications of goodwill impairment in the nine months ended September 30, 2018 and 2017. Fuel Tech reviews other intangible assets, which include customer lists and relationships, covenants not to compete, patent assets, tradenames, and acquired technologies, for impairment on a recurring basis or when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event that impairment indicators exist, a further analysis is performed and if the sum of the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Management considers historical experience and all available information at the time the estimates of future cash flows are made, however, the actual cash values that could be realized may differ from those that are estimated. In the second quarter of 2018, Fuel Tech recorded an abandonment charge of $317 associated with certain international patent assets which the Company elected to not maintain and abandon in certain international locations due to limited business opportunities in those regions. The abandonment charge was calculated by determining the net book values of the abandoned patent assets by deducting the accumulated amortization from the acquisition cost. The abandonment charge of $317 is included in “Intangible assets abandonment and building impairment” line in the accompanying Consolidated Statements of Operations for the nine months ended September 30, 2018. There were no other indications of intangible asset impairments for the nine month period ended September 30, 2018.

Goodwill and Other Intangibles

Goodwill is allocated among and evaluated for impairment at the reporting unit level, which is defined as an operating segment or one level below an operating segment. Fuel Tech has two reporting units for goodwill evaluation purposes: the FUEL CHEM^® technology segment and the APC technology segment. There is no goodwill associated with our APC segment. At both September 30, 2018 and December 31, 2017, our entire goodwill balance of $2,116 was allocated to the FUEL CHEM^® technology segment.

Goodwill is allocated to each of our reporting units after considering the nature of the net assets giving rise to the goodwill and how each reporting unit would enjoy the benefits and synergies of the net assets acquired. There were no indications of goodwill impairment in the nine months ended September 30, 2018 and 2017.

Fuel Tech reviews other intangible assets, which include customer lists and relationships, covenants not to compete, patent assets, tradenames, and acquired technologies, for impairment on a recurring basis or when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. In the event that impairment indicators exist, a further analysis is performed and if the sum of the expected undiscounted future cash flows resulting from the use of the asset is less than the carrying amount of the asset, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Management considers historical experience and all available information at the time the estimates of future cash flows are made, however, the actual cash values that could be realized may differ from those that are estimated.

In the second quarter of 2018, Fuel Tech recorded an abandonment charge of $317 associated with certain international patent assets which the Company elected to not maintain and abandon in certain international locations due to limited business opportunities in those regions. The abandonment charge was calculated by determining the net book values of the abandoned patent assets by deducting the accumulated amortization from the acquisition cost. The abandonment charge of $317 is included in “Intangible assets abandonment and building impairment” line in the accompanying Consolidated Statements of Operations for the nine months ended September 30, 2018.

There were no other indications of intangible asset impairments for the nine month period ended September 30, 2018.