Employee and Retiree Benefits (Postretirement Health Care and Deferred Compensation Benefits) (Details) - USD ($) $ in Thousands	Aug. 29, 2015	Aug. 30, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Postretirement health care benefit cost	$ 34,535	$ 36,930
Non-qualified deferred compensation	19,508	21,014
Executive share option plan liability	4,788	5,628
SERP benefit liability	2,649	2,974
Executive deferred compensation	299	213
Officers stock-based compensation	242	627
Total postretirement health care and deferred compensation benefits	62,021	67,386
Less current portion	(4,931)	(4,575)
Long-term postretirement health care and deferred compensation benefits	$ 57,090	$ 62,811