Impairment of Long-Lived Assets, Discontinued Operations, Property Held for Sale and Store Closings - Impairment Charges to Income from Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 13, 2019	Mar. 14, 2018	Mar. 13, 2019	Mar. 14, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Provision for asset impairments and restaurant closings	$ 1,195	$ 1,407	$ 2,422	$ 2,252
Net loss (gain) on disposition of property and equipment	$ (12,651)	$ (204)	(12,501)	18
Disposal Group, Disposed of by Sale, Not Discontinued Operation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Provision for asset impairments and restaurant closings			2,422	2,252
Net loss (gain) on disposition of property and equipment			(12,501)	18
Total			$ (10,079)	$ 2,270
Effect on EPS:
Basic (in dollars per share)			$ 0.34	$ (0.08)
Assuming dilution (in dollars per share)			$ 0.34	$ (0.08)