Employee Benefit Plans - Obligations and Funded Status (Details) - USD ($) $ in Thousands	12 Months Ended
	Aug. 29, 2020	Aug. 31, 2019	Aug. 25, 2018
Pension Plans
Change in benefit obligation:
Projected benefit obligation, beginning of year	$ 5,566	$ 7,449
Service cost	113	114	$ 115
Interest cost	131	260	257
Actuarial loss	169	163
Benefits paid	(224)	(50)
Settlements	(287)	(2,370)
Projected benefit obligation, end of year	5,468	5,566	7,449
Change in plan assets:
Fair value of plan assets, beginning of year	4,603	6,325
Actual return on plan assets	54	170
Employer contributions		528
Benefits paid	(224)	(50)
Settlements	(287)	(2,370)
Fair value of plan assets, end of year	4,146	4,603	6,325
Funded status (net amount recognized):	(1,322)	(963)
SERP
Change in benefit obligation:
Projected benefit obligation, beginning of year	35,967	27,547
Service cost	918	725	694
Interest cost	1,027	1,148	1,027
Actuarial loss	1,658	7,456
Benefits paid	(954)	(909)
Settlements		0
Projected benefit obligation, end of year	38,616	35,967	27,547
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):	$ (38,616)	$ (35,967)