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Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill.

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No definition available.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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Business Segment, Geographic and Quarterly Financial Data - Reporting Segment Net Sales and Gross Margin (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from external customers	$ 13,386	$ 13,548	$ 9,741	$ 8,491	$ 9,568	$ 12,596	$ 15,175	$ 17,822	$ 45,166	$ 55,161	$ 73,664
Cost of sales	$ (7,761)	$ (8,498)	$ (6,116)	$ (4,769)	$ (7,717)	$ (7,281)	$ (9,595)	$ (11,774)	(27,144)	(36,367)	(45,107)
Gross margin									18,022	18,794	28,557
Selling, general and administrative									(20,933)	(25,564)	(30,897)
Restructuring charge									(119)	(1,428)	(219)
Research and development									(1,070)	(1,752)	(1,447)
Building impairment									(2,965)	(2,074)	(1,425)
Operating loss from continuing operations									(7,065)	(12,024)	(5,431)
Air Pollution Control Segment
Revenues from external customers									27,808	34,052	43,485
Cost of sales									(18,478)	(25,370)	(30,612)
Gross margin									9,330	8,682	12,873
Selling, general and administrative									0	0	0
Restructuring charge									(58)	(537)	(149)
Research and development									0	0	0
Building impairment									0	0	(1,425)
Operating loss from continuing operations									9,272	8,145	11,299
FUEL CHEM Segment
Revenues from external customers									17,358	21,109	30,179
Cost of sales									(8,666)	(10,997)	(14,495)
Gross margin									8,692	10,112	15,684
Selling, general and administrative									0	0	0
Restructuring charge									(61)	(891)	(70)
Research and development									0	0	0
Building impairment									0	0	0
Operating loss from continuing operations									8,631	9,221	15,614
Other
Revenues from external customers									0	0	0
Cost of sales									0	0	0
Gross margin									0	0	0
Selling, general and administrative									(20,933)	(25,564)	(30,897)
Restructuring charge									0	0	0
Research and development									(1,070)	(1,752)	(1,447)
Building impairment									(2,965)	(2,074)	0
Operating loss from continuing operations									$ (24,968)	$ (29,390)	$ (32,344)