Asset Retirement Obligations - Narrative (Details)	12 Months Ended
	Aug. 26, 2017
Asset Retirement Obligations [Line Items]
Estimated impact of inflation per year	3.00%
Credit-adjusted risk-free rates, minimum	7.00%
Credit-adjusted risk-free rates, maximum	7.50%
Minimum
Asset Retirement Obligations [Line Items]
Remaining lives	1 year
Maximum
Asset Retirement Obligations [Line Items]
Remaining lives	27 years