Income Taxes (Schedule Of Deferred Tax Assets And Deferred Tax Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Postretirement and other employee benefits	$ 18,256	$ 18,395
Foreign tax credit and other carryforwards	55,103	111,325
Capitalized research and experimental costs	5,566	7,695
Environmental reserves	1,110	976
Inventory	14,863	14,251
Long-term contract option amortization	1,080	1,144
Provision for rationalization charges	232	351
Other	1,872	4,270
Total gross deferred tax assets	98,082	158,407
Less: valuation allowance	(13,736)	(58,446)
Total deferred tax assets	84,346	99,961
Deferred tax liabilities:
Fixed assets	56,659	59,521
Inventory	12,778	7,751
Goodwill and acquired intangibles	6,996	3,668
Other	2,468	3,138
Total deferred tax liabilities	78,901	74,078
Total deferred tax liabilities	$ 5,445	$ 25,883