Impairment of Long-Lived Assets - Additional Information (Detail)	12 Months Ended
	Sep. 30, 2011 Restaurant
Impaired Long-Lived Assets Held and Used [Line Items]
Projected variable and semi-variable restaurant operating costs increase percentage	1.50%
Projected food and packaging costs decrease percentage	1.00%
Number of restaurants impaired	0
Minimum
Impaired Long-Lived Assets Held and Used [Line Items]
Historical weighted average menu price increase percentage	1.50%
Projected fixed restaurant operating costs increase percentage	1.50%
Maximum
Impaired Long-Lived Assets Held and Used [Line Items]
Historical weighted average menu price increase percentage	6.00%
Projected fixed restaurant operating costs increase percentage	2.00%
Projected cash flows decline percentage	15.00%
Fiscal Year 2012 | Minimum
Impaired Long-Lived Assets Held and Used [Line Items]
Projected sales increase percentage	3.00%
Fiscal Year 2012 | Maximum
Impaired Long-Lived Assets Held and Used [Line Items]
Projected sales increase percentage	5.00%
Fiscal Year 2013 to 2024 | Minimum
Impaired Long-Lived Assets Held and Used [Line Items]
Projected sales increase percentage	2.00%
Fiscal Year 2013 to 2024 | Maximum
Impaired Long-Lived Assets Held and Used [Line Items]
Projected sales increase percentage	3.00%