Impairment of Long-Lived Assets, Discontinued Operations, Property Held for Sale and Store Closings (Details Textual)	3 Months Ended			6 Months Ended		12 Months Ended
	Mar. 15, 2017 USD ($) properties location property restaurant	Mar. 09, 2016 USD ($)	Nov. 18, 2009 location	Mar. 15, 2017 USD ($) properties location property restaurant	Mar. 09, 2016 USD ($) location	Aug. 31, 2016 USD ($) properties restaurant	Aug. 27, 2014 plan
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges	$ 5,963,000	$ 37,000		$ 6,250,000	$ 37,000
Number of restaurants with impaired assets | location				13
Number of restaurants with impaired goodwill | location				6	1
Net loss (gain) on disposition of property and equipment	329,000	$ (556,000)		$ 414,000	$ (835,000)
Assets of disposal group, number | properties				4		5
Property and equipment, net	185,067,000			$ 185,067,000		$ 193,218,000
Number of closure plans | plan							2
Property held for sale	3,900,000			3,900,000		5,500,000
Accrued lease termination expense	$ 65,000			$ 65,000		$ 151,000
Company-owned restaurants [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | restaurant	173			173		175
Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | properties	1			1
Impairment of leasehold				$ 0
Discontinued Operations [Member] | Company-owned restaurants [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Property and equipment, net	$ 1,900,000			$ 1,900,000
Cheeseburger in Paradise [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | location	6			6
Cheeseburger in Paradise [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | location	0			0
Lubys Cafetria [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Assets of disposal group, number | location			24
Discontinued Operations, Held-for-sale [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | property	4			4
Discontinued Operations, Held-for-sale [Member] | Lubys Cafetria [Member] | Discontinued Operations [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | location	1			1
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset impairment charges						$ 200,000
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member] | Lubys Cafetria [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | restaurant						1
Discontinued Operations, Disposed of by Means Other than Sale, Abandonment [Member] | Fuddruckers [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of restaurants | restaurant						3
Newer Properties [Member] | Minimum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Time span for future cash flow				20 years
Newer Properties [Member] | Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Time span for future cash flow				25 years
Older Properties [Member] | Minimum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Time span for future cash flow				5 years
Older Properties [Member] | Maximum [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Time span for future cash flow				10 years