Restructuring Textual 2 (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)	Dec. 31, 2018	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Number of Positions Eliminated	23
Advanced Materials
Restructuring Cost and Reserve [Line Items]
Number of Positions Eliminated		40
Performance Alloys and Composites
Restructuring Cost and Reserve [Line Items]
Gain (Loss) on Disposition of Property Plant Equipment	$ 1.4
Number of Positions Eliminated			13