Employee and Retiree Benefits (Changes in Postretirement Health Care Liability) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Aug. 30, 2014	Aug. 31, 2013	Aug. 25, 2012
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Balance at beginning of year	$ 36,244	$ 45,132
Interest cost	1,540	1,508	1,849
Service cost	393	574	539
Net benefits paid	(1,035)	(1,109)
Actuarial (gain) loss	3,368	(5,572)
Plan amendment	(3,580)	(4,289)
Balance at end of year	$ 36,930	$ 36,244	$ 45,132