Discontinued Operations (Summary Of Assets And Liabilities As Discontinued Operations) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 8,200	$ 8,200
Current assets held-for-sale	294,803	298,205
Deferred income taxes	98,714	88,526
Non-current assets held-for-sale	158,999	209,571
Current liabilities held-for-sale	133,006	158,182
Non-current liabilities held-for-sale	37,489	64,483
Tile Coatings [Member] | Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	8,200	8,200
Accounts receivable, net	160,174	151,975
Inventories	100,981	111,227
Other receivables	22,442	23,989
Other current assets	3,006	2,814
Current assets held-for-sale	294,803	298,205
Property, plant and equipment, net	99,429	105,802
Goodwill	3	43,511
Amortizable intangible assets, net	39,687	42,990
Deferred income taxes	14,425	14,962
Other non-current assets	5,455	2,306
Non-current assets held-for-sale	158,999	209,571
Total assets held-for-sale	453,802	507,776
Loans payable and current portion of long-term debt	3,678	5,838
Accounts payable	96,967	123,820
Accrued payrolls	4,838	3,396
Accrued expenses and other current liabilities	27,523	25,128
Current liabilities held-for-sale	133,006	158,182
Long-term debt, less current portion	25,805	54,173
Postretirement and pension liabilities	7,473	6,365
Other non-current liabilities	4,211	3,945
Non-current liabilities held-for-sale	37,489	64,483
Total liabilities held-for-sale	$ 170,495	$ 222,665