Business Segments (Schedule Of Identifiable Assets By Geographic Area, Property, Plant & Equipment, Net By Geographic Area) (Details) - USD ($) $ in Thousands		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	$ 712,668		$ 707,373
Cash and cash equivalents		31,422	[1]	34,397	[1]	$ 36,491	$ 29,511
Property, Plant & Equipment, Net by Geographic Area, Total		242,890		228,369
Property, Plant & Equipment, Net of Discontinued operations by Geographic Area, Total	[1]	242,890		228,369
United States
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1],[2]	458,066		454,178
Property, Plant & Equipment, Net by Geographic Area, Total	[1],[2]	181,989		166,550
General Corporate
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1],[2]	111,788		100,920
Property, Plant & Equipment, Net by Geographic Area, Total	[1],[2]	1,389		1,401
Operations Outside The United States | Brazil
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	54,698		52,796
Property, Plant & Equipment, Net by Geographic Area, Total	[1]	20,542		16,072
Operations Outside The United States | NETHERLANDS
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	12,579		15,020
Property, Plant & Equipment, Net by Geographic Area, Total	[1]	5,729		6,005
Operations Outside The United States | The Netherlands
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	18,056		21,610
Property, Plant & Equipment, Net by Geographic Area, Total	[1]	16,210		19,213
Operations Outside The United States | Hungary
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	20,179		23,615
Property, Plant & Equipment, Net by Geographic Area, Total	[1]	13,715		15,436
Operations Outside The United States | India
Segment Reporting Information [Line Items]
Identifiable Assets by Geographic Area, Total	[1]	5,880		4,837
Property, Plant & Equipment, Net by Geographic Area, Total	[1]	$ 3,316		$ 3,692

[1] Information on exports and foreign operations are provided on the previous page. Cash and cash equivalents includes funds held in locations outside the U.S. of $23.0 million and $31.1 million at December 31, 2019 and 2018, respectively. Export sales relate almost entirely to PE Films. Operations outside the U.S. in The Netherlands, Hungary, China and India also relate to PE Films. Operations in Brazil are primarily related to Flexible Packaging Films, but also include PE Films operations. Sales from locations in The Netherlands and Hungary are primarily to customers located in Europe. Sales from locations in China (Guangzhou and Shanghai) are primarily to customers located in China, but also include other customers in Asia.

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