Employee Benefit Plans - Obligations and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 28, 2021	Aug. 29, 2020	Aug. 31, 2019
Pension Plans
Change in benefit obligation:
Projected benefit obligation, beginning of year	$ 5,468	$ 5,566
Service cost	71	113	$ 114
Interest cost	104	131	260
Actuarial (gain) loss	(225)	169
Benefits paid	(28)	(224)
Settlements	(355)	(287)
Projected benefit obligation, end of year	5,035	5,468	5,566
Change in plan assets:
Fair value of plan assets, beginning of year	4,146	4,603
Actual return on plan assets	33	54
Benefits paid	(28)	(224)
Settlements	(355)	(287)
Fair value of plan assets, end of year	3,796	4,146	4,603
Funded status (net amount recognized):	(1,239)	(1,322)
SERP
Change in benefit obligation:
Projected benefit obligation, beginning of year	38,616	35,967
Service cost	1,100	918	725
Interest cost	943	1,027	1,148
Actuarial (gain) loss	(2,890)	1,658
Benefits paid	(1,125)	(954)
Settlements		0
Projected benefit obligation, end of year	36,644	38,616	35,967
Change in plan assets:
Fair value of plan assets, beginning of year	0	0
Actual return on plan assets		0
Employer contributions		0
Benefits paid		0
Settlements		0
Fair value of plan assets, end of year		0	$ 0
Funded status (net amount recognized):	$ (36,644)	$ (38,616)