Employee and Retiree Benefits (Postretirement Narrative) (Details) (USD $)	12 Months Ended
	Aug. 30, 2014	Aug. 31, 2013
Compensation and Retirement Disclosure [Abstract]
Postretirement health care benefits age requirement before distribution occurs	55 years
Postretirement health care benefits continuous service requirement	15 years
Dollar cap liability reduction	10.00%
Plan amendment	$ (3,580,000)	$ (4,289,000)
Accumulated postretirement benefit obligation discount rate	3.90%	4.60%
Actuarial (gain) loss	3,368,000	(5,572,000)
Pension and Other Postretirement Benefit Plans, Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year [Abstract]
Prior service cost (credit)	(5,200,000)
Actuarial net gains (losses)	$ (1,300,000)