Benefit Plans - Schedule of Amortization from Other Accumulated Comprehensive Income into Net Period Benefit Costs (Details) $ in Thousands	Aug. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, health care benefits annual rate of increase in the per capita cost	7.10%
Defined benefit plan, health care benefits, decrease in the per capita cost trend rate	4.50%
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fiscal 2018 Amortization of prior service cost (credit)	$ 178
Fiscal 2018 Amortization of net actuarial (gain) loss	21,790
Non-Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fiscal 2018 Amortization of prior service cost (credit)	(114)
Fiscal 2018 Amortization of net actuarial (gain) loss	212
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Fiscal 2018 Amortization of prior service cost (credit)	(445)
Fiscal 2018 Amortization of net actuarial (gain) loss	$ (1,365)