Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2020	Apr. 14, 2021	Jun. 30, 2020
Document Information Line Items
Entity Registrant Name	TRANS LUX Corp
Document Type	10-K
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		13,446,276
Entity Public Float			$ 789,000
Amendment Flag	false
Entity Central Index Key	0000099106
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	false
Entity Interactive Data Current	Yes