Employee Benefit Plans - Amounts Recorded in Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Aug. 31, 2019	Aug. 25, 2018
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred tax assets	$ 254	$ 362
Accrued liabilities	963	1,124
Accumulated other comprehensive loss	(741)	(1,037)
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred tax assets	2,912	1,081
Accrued liabilities	35,967	27,547
Accumulated other comprehensive loss	$ (8,509)	$ (3,098)