Revenue Recognition (Summary of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Net sales	$ 55,171	$ 56,568	$ 70,997	$ 60,271	$ 57,063	$ 69,056	$ 66,071	$ 63,737	$ 243,007	$ 255,927	$ 202,643
Specialty Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales									201,120	209,203
Premium Alloys [Member]
Disaggregation Of Revenue [Line Items]
Net sales									37,618	41,144
Conversion Services and Other Sales [Member]
Disaggregation Of Revenue [Line Items]
Net sales									$ 4,269	$ 5,580