Employee and Retiree Benefits (Postretirement Health Care and Deferred Compensation Benefits) (Details) - USD ($) $ in Thousands	May 27, 2017	Aug. 27, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Postretirement health care benefit cost	$ 0	$ 6,346
Non-qualified deferred compensation	16,851	18,003
Executive share option plan liability	1,914	3,341
SERP benefit liability	2,428	2,681
Executive deferred compensation	510	389
Officer stock-based compensation	1,048	763
Total deferred compensation and postretirement health care benefits	22,751	31,523
Less current portion	(3,769)	(4,574)
Long-term deferred compensation and postretirement health care benefits	$ 18,982	$ 26,949