Employee Benefit Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 30, 2025	Aug. 31, 2024	Aug. 26, 2023
UniFirst Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 73	$ 74	$ 73
Interest cost	148	159	147
Expected return on assets	$ (91)	$ (90)	$ (101)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent
Amortization of prior service cost	$ 21	$ 21	$ 21
Other events	(10)		(12)
Net periodic benefit cost	141	164	128
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	390	405	486
Interest cost	1,239	1,255	1,191
Amortization of actuarial gain	(41)	(116)
Net periodic benefit cost	$ 1,588	$ 1,544	$ 1,677