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Derivative Financial Instruments (Schedule Of Pretax Effect On Net Income (Loss) And Other Comprehensive Income (Loss) Of Derivative Instruments Classified As Cash Flow Hedges) (Details) - Cash Flow Derivative Hedges - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Aluminum Futures Contracts | Cost of goods sold
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	$ 2,919	$ 1,158	$ 6,629	$ (1,637)
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income (effective portion)	2,160	(575)	4,172	(2,766)
Foreign Currency Forwards | Cost of goods sold
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	0	0	0	0
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income (effective portion)	15	15	48	46
Foreign Currency Forwards | Selling, general & admin
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	(1,670)	(655)	(1,892)	(6,015)
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income (effective portion)	$ (34)	$ (1,767)	$ (183)	$ (4,359)

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

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Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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