Revenue Recognition (Summary of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Net sales	$ 52,479	$ 70,997	$ 110,973	$ 131,268
Specialty Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales	39,102	57,017	89,022	106,781
Premium Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales	12,442	12,814	20,106	22,184
Conversion Services and Other Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 935	$ 1,166	$ 1,845	$ 2,303