Benefit Plans - Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2022	Nov. 30, 2021
Qualified Pension Benefits
Component of net periodic benefit costs: [Abstract]
Service cost	$ 9,645	$ 11,569
Interest cost	7,647	4,292
Expected return on assets	(10,782)	(10,990)
Prior service cost (credit) amortization	37	44
Actuarial loss (gain) amortization	468	5,852
Net periodic benefit cost (benefit)	7,015	10,767
Non-Qualified Pension Benefits
Component of net periodic benefit costs: [Abstract]
Service cost	460	232
Interest cost	185	70
Expected return on assets	0	0
Prior service cost (credit) amortization	(29)	(29)
Actuarial loss (gain) amortization	61	120
Net periodic benefit cost (benefit)	677	393
Other Benefits
Component of net periodic benefit costs: [Abstract]
Service cost	168	249
Interest cost	259	126
Expected return on assets	0	0
Prior service cost (credit) amortization	(111)	(111)
Actuarial loss (gain) amortization	(404)	(315)
Net periodic benefit cost (benefit)	$ (88)	$ (51)