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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Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Goodwill (Additional Disclosures) (Details)	3 Months Ended					12 Months Ended
Goodwill (Additional Disclosures) (Details)	Jun. 30, 2018 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2018 USD ($) reporting_unit	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting units \| reporting_unit						0
Goodwill [Line Items]
Goodwill impairment recognized		$ 0	$ 0	$ 0	$ 0	$ 37,180,000	$ 0	$ 0
Energy Chemical Technologies
Goodwill [Line Items]
Goodwill impairment recognized	$ 37,200,000