Reportable Segments - Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 18, 2020	Nov. 18, 2009
Sales:
Total sales	$ 41,947	$ 41,947
Segment level profit:
Segment level profit	5,086
Depreciation and amortization:
Depreciation and amortization	2,142	2,142
Capital expenditures:
Capital expenditures	433
Loss before income taxes and discontinued operations:
Segment level profit	5,086
Depreciation and amortization	(2,142)	(2,142)
Selling, general and administrative expenses	(4,267)	(4,267)
Other charges	(416)	(416)
Net provision for asset impairments and restaurant closings	85
Net gain on disposition of property and equipment	(117)	(117)
Interest income	8	8
Interest expense	(1,212)	(1,212)
Other income, net	30	30
Loss before income taxes and discontinued operations	(2,945)	$ (2,945)
Luby's cafeterias
Sales:
Total sales	31,949
Segment level profit:
Segment level profit	4,896
Loss before income taxes and discontinued operations:
Segment level profit	4,896
Fuddruckers restaurants
Sales:
Total sales	4,550
Segment level profit:
Segment level profit	(412)
Loss before income taxes and discontinued operations:
Segment level profit	(412)
Culinary contract services
Sales:
Total sales	4,918
Segment level profit:
Segment level profit	451
Loss before income taxes and discontinued operations:
Segment level profit	451
Fuddruckers franchise operations
Sales:
Total sales	530
Segment level profit:
Segment level profit	236
Loss before income taxes and discontinued operations:
Segment level profit	236
Cheeseburger in Paradise restaurants
Segment level profit:
Segment level profit	(85)
Loss before income taxes and discontinued operations:
Segment level profit	(85)
Operating Segments | Luby's cafeterias
Depreciation and amortization:
Depreciation and amortization	1,530
Capital expenditures:
Capital expenditures	416
Loss before income taxes and discontinued operations:
Depreciation and amortization	(1,530)
Operating Segments | Fuddruckers restaurants
Depreciation and amortization:
Depreciation and amortization	167
Capital expenditures:
Capital expenditures	17
Loss before income taxes and discontinued operations:
Depreciation and amortization	(167)
Operating Segments | Culinary contract services
Depreciation and amortization:
Depreciation and amortization	8
Loss before income taxes and discontinued operations:
Depreciation and amortization	(8)
Operating Segments | Fuddruckers franchise operations
Depreciation and amortization:
Depreciation and amortization	1
Loss before income taxes and discontinued operations:
Depreciation and amortization	(1)
Corporate
Depreciation and amortization:
Depreciation and amortization	436
Loss before income taxes and discontinued operations:
Depreciation and amortization	$ (436)