Fair Value Measurements - Non-recurring Fair Value Measurements Related to Impaired Property and Equipment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 15, 2017	Mar. 09, 2016	Mar. 15, 2017	Mar. 09, 2016	Aug. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total Nonrecurring Fair Value Measurements, Total Impairments	$ (5,963,000)	$ (37,000)	$ (6,250,000)	$ (37,000)
Goodwill	1,068,000		1,068,000		$ 1,605,000
Property and equipment, net	185,067,000		185,067,000		$ 193,218,000
Continuing Operations [Member] | Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property held for sale	3,213,000		3,213,000
Property held for sale, Total Impairments			(419,000)
Goodwill	0	0	0	0
Goodwill, impairment loss			(537,000)	(38,000)
Property and equipment related to company-owned restaurants	1,410,000		1,410,000
Property and equipment related to company-owned restaurants, total impairments			(5,226,000)
Total Nonrecurring Fair Value Measurements	4,623,000	0	4,623,000	0
Total Nonrecurring Fair Value Measurements, Total Impairments			(6,182,000)	(38,000)
Property held for sale, net	4,800,000		4,800,000
Proceeds on sales and costs to sell			1,200,000
Goodwill	537,000	38,000	537,000	38,000
Continuing Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Company-owned restaurants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property and equipment related to company-owned restaurants	1,400,000		1,400,000
Property and equipment related to company-owned restaurants, total impairments			(5,200,000)
Property and equipment, net	6,600,000		6,600,000
Continuing Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property held for sale	0		0
Goodwill	0	0	0	0
Property and equipment related to company-owned restaurants	0		0
Total Nonrecurring Fair Value Measurements	0	0	0	0
Continuing Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property held for sale	0		0
Goodwill	0	0	0	0
Property and equipment related to company-owned restaurants	0		0
Total Nonrecurring Fair Value Measurements	0	0	0	0
Continuing Operations [Member] | Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property held for sale	3,213,000		3,213,000
Goodwill	0	0	0	0
Property and equipment related to company-owned restaurants	1,410,000		1,410,000
Total Nonrecurring Fair Value Measurements	$ 4,623,000	$ 0	$ 4,623,000	$ 0