Employee Benefit Plans - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 27, 2022	Aug. 28, 2021	Aug. 29, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contributions charged to expense under the plan	$ 18,200	$ 19,900	$ 16,600
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts charged to expense related to the plan	1,500	2,900	2,600
Accumulated benefit obligations	24,600	30,600
Plan funded amount	(27,562)	(36,644)
UniFirst Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts charged to expense related to the plan	$ 100	200	200
Minimum annual interest rate	3.25%
Textilease Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts charged to expense related to the plan	$ 0	0	$ 500
Minimum annual interest rate	1.50%
Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated benefit obligations	$ 3,800	5,000
Plan funded amount	(537)	$ (1,239)
Nonqualified Deferred Compensation Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Plan funded amount	1,300
NQDC Plan assets	$ 1,300