Basis Of Presentation	9 Months Ended
Basis Of Presentation	Sep. 30, 2021
Basis Of Presentation [Abstract]
Basis Of Presentation	BASIS OF PRESENTATION In the opinion of management, the accompanying condensed consolidated financial statements of Tredegar Corporation and its subsidiaries (“Tredegar,” “the Company,” “we,” “us” or “our”) contain all adjustments necessary to state fairly, in all material respects, Tredegar’s consolidated financial position as of September 30, 2021, the consolidated results of operations for the three and nine months ended September 30, 2021 and 2020, the consolidated cash flows for the nine months ended September 30, 2021 and 2020, and the consolidated changes in shareholders’ equity for the three and nine months ended September 30, 2021 and 2020, in accordance with U.S. generally accepted accounting principles (“GAAP”). All such adjustments, unless otherwise detailed in the notes to the condensed consolidated financial statements, are deemed to be of a normal, recurring nature. The Company operates on a calendar fiscal year except for the Aluminum Extrusions segment, which operates on a 52/53-week fiscal year basis. As such, the fiscal third quarter for 2021 and 2020 for this segment references 13-week periods ended September 25, 2021 and September 27, 2020. The Company does not believe the impact of reporting the results of this segment as stated above is material to the consolidated financial results. The Company may fund or receive cash from the Aluminum Extrusions segment based on Aluminum Extrusion’s cash flows from operations during the intervening period from Aluminum Extrusion’s fiscal quarter end and the Company’s fiscal quarter end. There was no intercompany funding with Aluminum Extrusions between September 25, 2021 and September 30, 2021. As of September 30, 2021 and December 31, 2020, the Company’s cash and cash equivalents declined by $0.5 million and $3.8 million, respectively, since the Company made payments to the Aluminum Extrusions segment to fund its working capital during the intervening period. The financial position data as of December 31, 2020 that is included herein was derived from the audited consolidated financial statements provided in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (“2020 Form 10-K”) but does not include all disclosures required by GAAP. These financial statements should be read in conjunction with the consolidated financial statements and related notes included in the 2020 Form 10-K. On October 30, 2020, the Company completed the sale of its personal care films business (“Personal Care Films”), which was part of its PE Films segment. The transaction excluded the packaging film lines and related operations located at the Pottsville, Pennsylvania manufacturing site (“Pottsville Packaging”), which are now being reported within the Surface Protection component of PE Films. All historical results for Personal Care Films have been presented as discontinued operations. On December 31, 2020, the Company completed the sale of Bright View Technologies, which was part of its PE Films segment. The sale did not represent a strategic shift nor did it have a major effect on the Company's historical and ongoing operations, thus all financial information for Bright View Technologies has been presented in continuing operations. The results of operations for the three and nine months ended September 30, 2021, are not necessarily indicative of the results to be expected for the full year. Accounting Standards Adopted: In December 2019, the Financial Accounting Standards Board issued Accounting Standards Update ("ASU") 2019-12, which simplifies the accounting for income taxes by eliminating certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period, hybrid taxes and the recognition of deferred tax liabilities for outside basis differences. It also clarifies and simplifies other aspects of the accounting for income taxes. In the first quarter of 2021, the Company adopted ASU 2019-12, which did not have a material impact on the Company's consolidated financial statements.