Employee Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	Aug. 30, 2025	Aug. 31, 2024
UniFirst Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain	$ 36	$ 113
Unrecognized prior service cost	(51)	(73)
Accumulated other comprehensive income (loss)	(15)	40
SERP
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial gain	5,459	2,950
Accumulated other comprehensive income (loss)	$ 5,459	$ 2,950

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant