Acquisitions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 25, 2012	Aug. 27, 2011	Aug. 28, 2010
Finite-Lived Intangible Assets [Line Items]
Total intangible assets and goodwill acquired	$ 456	$ 26,367
Customer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life in Years	11.6	14.4
Total intangible assets and goodwill acquired	402	9,588
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Life in Years	13.8	5.1
Total intangible assets and goodwill acquired	25	765
Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Number of businesses acquired	0	9	9
Tangible assets acquired	0	6,189	3,795
Intangible assets and goodwill acquired	0	26,367	17,113
Acquisition of businesses	$ 0	$ 32,556	$ 20,908