Revenue Recognition (Summary of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Net sales	$ 37,434	$ 56,568	$ 148,407	$ 187,836
Specialty Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales	27,847	47,730	116,869	154,511
Premium Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales	9,165	8,043	29,271	30,227
Conversion Services and Other Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales	$ 422	$ 795	$ 2,267	$ 3,098