Business Segment, Geographic and Major Customer Information (Assets by Reportable Segments) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Assets	$ 231,847	$ 285,883
Held for sale	0	118,470
Operating Segments
Segment Reporting Information [Line Items]
Assets	231,847	167,413
Operating Segments \| Energy Chemistry Technologies
Segment Reporting Information [Line Items]
Assets	117,357	139,205
Corporate and Other
Segment Reporting Information [Line Items]
Assets	$ 114,490	$ 28,208

Amount classified as assets attributable to disposal group held for sale or disposed of.

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