Derivative Financial Instruments (Summary Of Location And Fair Value Of Derivative Financial Instruments) (Details) - Aluminum Futures Contracts - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Net asset (liability), Fair Value	$ (108)	$ (1,753)
Derivatives Designated As Hedging Instruments [Member] | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	225	44
Liability derivatives: Fair Value	(333)	(1,797)
Derivatives Not Designated As Hedging Instruments | Accrued Expenses [Member]
Derivatives, Fair Value [Line Items]
Liability derivatives: Fair Value	$ 0	$ 0