Employee Benefit Plans - Schedule of Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Aug. 29, 2026	Aug. 30, 2025
UniFirst Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial (loss) gain	$ (159)	$ 36
Unrecognized prior service cost	(30)	(51)
Accumulated other comprehensive (loss) income	(189)	(15)
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial (loss) gain	6,645	5,459
Unrecognized prior service cost	0	0
Accumulated other comprehensive (loss) income	$ 6,645	$ 5,459