Fair Value Measurements (Additional Disclosures) (Details) - USD ($)	3 Months Ended					12 Months Ended
	Jun. 30, 2018	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill		$ 0	$ 0	$ 0	$ 0	$ 37,180,000	$ 0	$ 0
Impairment related to property and equipment						0	0	0
Impairment of related to other intangible assets						0	0	$ 0
Cash equivalents						$ 0	$ 0
Energy Chemical Technologies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of goodwill	$ 37,200,000