Accumulated Other Comprehensive Income (Loss) (Schedule Of After-Tax Changes In Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Selling, general and administrative	$ 23,130	$ 20,676	$ 69,006	$ 63,452
Beginning of Period			(179,987)	(176,669)
Other comprehensive income (loss) before reclassifications			(9,356)	(14,616)
Amounts reclassified from accumulated other comprehensive income (loss)			8,445	8,080
Net other comprehensive income (loss) - current period	(5,054)	(1,664)	(911)	(6,536)
End of Period	(180,898)	(183,205)	(180,898)	(183,205)
Income (loss) before income taxes	17,090	(40,899)	59,819	1,821
Income Tax Expense (Benefit)	(43)	(6,699)	8,424	3,135
Net income	17,133	(34,200)	51,395	(1,314)
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of Period			(96,940)	(86,178)
Other comprehensive income (loss) before reclassifications			(6,291)	(11,571)
Amounts reclassified from accumulated other comprehensive income (loss)			0	0
Net other comprehensive income (loss) - current period			(6,291)	(11,571)
End of Period	(103,231)	(97,749)	(103,231)	(97,749)
Gain (Loss) on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of Period			(1,601)	459
Other comprehensive income (loss) before reclassifications			(3,065)	(3,045)
Amounts reclassified from accumulated other comprehensive income (loss)			2,209	154
Net other comprehensive income (loss) - current period			(856)	(2,891)
End of Period	(2,457)	(2,432)	(2,457)	(2,432)
Pension & Other Post-retirement Benefit Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning of Period			(81,446)	(90,950)
Other comprehensive income (loss) before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive income (loss)			6,236	7,926
Net other comprehensive income (loss) - current period			6,236	7,926
End of Period	(75,210)	(83,024)	(75,210)	(83,024)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Gain (Loss) on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (loss) before income taxes	(902)	(492)	(2,654)	64
Income Tax Expense (Benefit)	(179)	23	(445)	218
Net income	(723)	(515)	(2,209)	(154)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Pension & Other Post-retirement Benefit Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income Tax Expense (Benefit)	(593)	(789)	(1,778)	(2,312)
Net income	(2,079)	(2,703)	(6,236)	(7,926)
Amortization Of Prior Service Costs And Net Gains Loss	(2,672)	(3,492)	(8,014)	(10,238)
Aluminum Futures Contracts [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gain (Loss) on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of goods sold	(816)	300	2,039	(1,244)
Cost of Sales [Member] | Foreign Currency Forward Contracts [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Gain (Loss) on Derivative Financial Instruments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Cost of goods sold	$ 15	$ 15	$ 46	$ 46