Cover - USD ($) $ in Thousands	12 Months Ended
	Aug. 26, 2020	Nov. 24, 2020	Mar. 11, 2020
Entity Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Aug. 26, 2020
Current Fiscal Year End Date	--08-26
Document Transition Report	false
Entity File Number	001-08308
Entity Registrant Name	Luby's, Inc.
Entity Central Index Key	0000016099
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-1335253
Entity Address, Address Line One	13111 Northwest Freeway
Entity Address, Address Line Two	Suite 600
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77040
City Area Code	713
Local Phone Number	329-6800
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 36,624
Entity Common Stock, Shares Outstanding		30,678,769
Documents Incorporated by Reference	Documents incorporated by reference: None
Common Stock
Entity Information [Line Items]
Title of 12(b) Security	Common Stock ($0.32 par value per share)
Trading Symbol	LUB
Security Exchange Name	NYSE
Common Stock Purchase Rights
Entity Information [Line Items]
Title of 12(b) Security	Common Stock Purchase Rights
Trading Symbol	N/A
Security Exchange Name	NYSE