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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of increase (decrease) in cash. Cash is the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Includes effect from exchange rate changes.

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Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Summary Of Significant Accounting Policies (Narrative) (Details). - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary Of Significant Accounting Policies [Line Items]
Interest Costs Capitalized	$ 100	$ 300	$ 100
Foreign Currency Transaction Gain (Loss), before Tax	600	600	100
Cash and cash equivalents	$ 11,846	31,422	34,397	$ 36,491
Investments, percentage of voting ownership interest	50.00%
Goodwill, Impairment Loss	$ 13,696	0	0
Goodwill, Impairment Loss, Net of Tax	10,500
Goodwill	$ 67,708	$ 81,404	$ 81,404
Incremental shares excluded from the calculation of incremental shares attributable to stock options and restricted stock	1,212,375	209,592	726,475
Asset Impairment Charges	$ 52,326	$ 0	$ 0
Cash	11,800	31,400
Cash, Period Increase (Decrease)	3,800
Foreign Country
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 9,400	8,900
Minimum \| Buildings And Land Improvements
Summary Of Significant Accounting Policies [Line Items]
Average useful life	5 years
Minimum \| Machinery and Equipment
Summary Of Significant Accounting Policies [Line Items]
Average useful life	2 years
Maximum \| Buildings And Land Improvements
Summary Of Significant Accounting Policies [Line Items]
Average useful life	40 years
Maximum \| Machinery and Equipment
Summary Of Significant Accounting Policies [Line Items]
Average useful life	20 years
Aluminum Extrusions
Summary Of Significant Accounting Policies [Line Items]
Goodwill, Impairment Loss	$ 13,696	0	0
Goodwill	$ 10,370	24,066	$ 24,066
Asset Impairment Charges		$ (10,000)
Customer Relationships [Member] \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	10 years
Customer Relationships [Member] \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	12 years
Trade Names [Member] \| Minimum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	5 years
Trade Names [Member] \| Maximum
Summary Of Significant Accounting Policies [Line Items]
Finite-Lived Intangible Asset, Useful Life	13 years