Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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Goodwill and Other Intangibles (Details)	3 Months Ended
Goodwill and Other Intangibles (Details)	Mar. 31, 2020 USD ($) reporting_unit	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Goodwill [Line Items]
Number of reporting units \| reporting_unit	2
Goodwill	$ 2,116,000		$ 2,116,000
Goodwill impairments	0	$ 0
Air Pollution Control Segment
Goodwill [Line Items]
Goodwill	0
FUEL CHEM Segment
Goodwill [Line Items]
Goodwill	$ 2,116,000		$ 2,116,000