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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) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Foreign Currency Forwards And Options [Member] | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	$ 16	$ 16	$ 31	$ 31
Foreign Currency Forwards And Options [Member] | Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	(378)		(419)
Cash Flow Derivative Hedges | Aluminum Futures Contracts
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	1,457	(322)	1,065	524
Cash Flow Derivative Hedges | Aluminum Futures Contracts | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) reclassified from accumulated other comprehensive income (loss) to net income effective portion)	712	321	944	554
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	0	$ 0		$ 0
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options | Cost Of Sales
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)			0
Cash Flow Derivative Hedges | Foreign Currency Forwards And Options | Selling, General and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of pretax gain (loss) recognized in other comprehensive income (loss)	$ (1,849)		$ (1,679)

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+ References

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

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