Financial Instruments (Schedule Of Pretax Effect On Net Income (Loss) And Other Comprehensive Income (Loss) Of Derivative Instruments Classified As Cash Flow Hedges) (Details) - Aluminum Futures Contracts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	$ (1,123)	$ 1,501	$ 394
Cost of Sales [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net	$ 1,069	$ 1,210	$ (1,630)