Basis Of Presentation	9 Months Ended
Basis Of Presentation	Sep. 30, 2022
Basis Of Presentation [Abstract]
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 condensed consolidated financial position as of September 30, 2022, the condensed consolidated results of operations for the three and nine months ended September 30, 2022 and 2021, the condensed consolidated cash flows for the nine months ended September 30, 2022 and 2021, and the condensed consolidated changes in shareholders’ equity for the nine months ended September 30, 2022 and 2021, 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 2022 and 2021 for this segment references 13-week periods ended September 25, 2022 and September 26, 2021. 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, 2022 and September 30, 2022. The financial position data as of December 31, 2021 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, 2021 (“2021 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 2021 Form 10-K. The results of operations for the three and nine months ended September 30, 2022, are not necessarily indicative of the results to be expected for the full year. Risks and Uncertainties During the three months ended September 30, 2022, events and circumstances indicated that the Surface Protection reporting unit ("Surface Protection"), which is also the asset group, might be impaired. The Company performed a goodwill and long-lived impairment analysis for Surface Protection and determined that the fair value of Surface Protection exceeded its carrying value. Given the uncertain demand for Surface Protections products, it is reasonably possible that the cash flow estimates used in deriving such fair value measurements may change in the future. As of September 30, 2022, the Surface Protection reporting unit had goodwill of $57.3 million and long-lived identifiable assets of $29.5 million. Accounting Standards Adopted In March 2020, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2020-04, which provides optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by the discontinuation of the London Interbank Offered Rate or by another reference rate expected to be discontinued because of reference rate reform. The guidance was effective beginning March 12, 2020 and can be applied prospectively through December 31, 2022. In January 2021, the FASB issued ASU 2021-01, which clarified the scope and application of the original guidance. In the second quarter of 2022, the Company adopted ASU 2020-04, which did not have a material impact on the Company’s consolidated financial statements. Accounting Standards Not Yet Adopted In September 2022, the FASB issued ASU 2022-04, which requires that a buyer in a supplier finance program disclose sufficient information about the program to allow a user of financial statements to understand the program’s nature, activity during the period, changes from period to period, and potential magnitude. The guidance is effective for annual periods beginning after December 15, 2022, with early adoption permitted. The Company is currently evaluating the potential impact of adopting this guidance, but does not expect it to have a material impact on the consolidated financial statements.