Employee Benefit Plans - Obligations and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2024	Aug. 26, 2023	Aug. 27, 2022
UniFirst Plan
Change in benefit obligation:
Projected benefit obligation, beginning of year	$ 3,549	$ 3,837
Service cost	74	73	$ 72
Interest cost	159	147	104
Actuarial (gain) loss	(28)	(220)
Benefits paid	(145)	(17)
Settlements/Curtailments		(271)
Projected benefit obligation, end of year	3,609	3,549	3,837
Change in plan assets:
Fair value of plan assets, beginning of year	2,986	3,300
Actual return on plan assets	20	(26)
Employer Contributions	247
Benefits paid	(145)	(17)
Settlements/Curtailments		(271)
Fair value of plan assets, end of year	3,108	2,986	3,300
Funded status (net amount recognized):	(501)	(563)
SERP
Change in benefit obligation:
Projected benefit obligation, beginning of year	25,119	27,562
Service cost	405	486	919
Interest cost	1,255	1,191	928
Actuarial (gain) loss	465	(2,811)
Benefits paid	(1,364)	(1,309)
Projected benefit obligation, end of year	25,880	25,119	$ 27,562
Change in plan assets:
Funded status (net amount recognized):	$ (25,880)	$ (25,119)