Consolidated Statements Of Shareholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Retained Earnings	Trust For Savings Restoration Plan	Foreign Currency Translation	Gain (Loss) On Derivative Financial Instruments	Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Balance at Dec. 31, 2018	$ 354,857	$ 38,892	$ 497,511	$ (1,559)	$ (96,940)	$ (1,601)	$ (81,446)
Balance, shares at Dec. 31, 2018		33,176,024
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	48,259		48,259
Foreign currency translation adjustment	(3,723)				(3,723)
Derivative financial instruments adjustment	294					294
Net actuarial gains (losses) and prior service costs	(22,508)						(22,508)
Amortization of prior service costs and net gains or losses	8,273						8,273
Cash dividends declared	(15,325)		(15,325)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		228,959
Share Based Compensation Expense, Value	7,292	$ 7,292
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		(49,444)
Issued upon exercise of stock options & other	184	$ 184
Issued upon exercise of stock options (including related income tax benefits) & other, shares		9,500
Tredegar common stock purchased by trust for savings restoration plan	0		33	(33)
Balance at Dec. 31, 2019	376,749	$ 45,514	530,478	(1,592)	(100,663)	(1,307)	(95,681)
Balance, shares at Dec. 31, 2019		33,365,039
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payment, Tax Withholding, Share-based Payment Arrangement	(854)	$ (854)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	0
Net income (loss)	(75,444)		(75,444)
Foreign currency translation adjustment	(8,781)				(8,781)
Derivative financial instruments adjustment	3,571					3,571
Net actuarial gains (losses) and prior service costs	(12,197)						(12,197)
Amortization of prior service costs and net gains or losses	11,359						11,359
Cash dividends declared	(216,049)		(216,049)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		131,354
Share Based Compensation Expense, Value	5,402	$ 5,402
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		(39,217)
Tredegar common stock purchased by trust for savings restoration plan	0		495	(495)
Balance at Dec. 31, 2020	109,055	$ 50,066	239,480	(2,087)	(84,149)	2,264	(96,519)
Balance, shares at Dec. 31, 2020		33,457,176
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payment, Tax Withholding, Share-based Payment Arrangement	(850)	$ (850)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	25,295
Net income (loss)	57,826		57,826
Foreign currency translation adjustment	(1,643)				(1,643)
Derivative financial instruments adjustment	(1,363)					(1,363)
Net actuarial gains (losses) and prior service costs	18,720						18,720
Amortization of prior service costs and net gains or losses	13,186						13,186
Cash dividends declared	(16,167)		(16,167)
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures		229,014
Share Based Compensation Expense, Value	4,783	$ 4,783
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		(17,266)
Tredegar common stock purchased by trust for savings restoration plan	0		48	(48)
Balance at Dec. 31, 2021	184,722	$ 55,174	$ 281,187	$ (2,135)	$ (85,792)	$ 901	$ (64,613)
Balance, shares at Dec. 31, 2021		33,736,629
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Payment, Tax Withholding, Share-based Payment Arrangement	(590)	$ (590)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, Net of Tax	$ 0