Benefit Plans Schedule of Net Benefit Costs (Tables)

6 Months Ended

Feb. 28, 2022

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs of Assumptions Used

Components of net periodic benefit costs for the three and six months ended February 28, 2022 and 2021, are as follows:

	Three Months Ended February 28,
	Qualified Pension Benefits				Nonqualified Pension Benefits				Other Benefits
	2022		2021		2022		2021		2022		2021
Components of net periodic benefit costs:	(Dollars in thousands)
Service cost	$	11,569	$	11,307	$	232	$	108	$	249	$	297
Interest cost	4,292		4,141		70		68		126		123
Expected return on assets	(10,990)		(10,910)		—		—		—		—
Prior service cost (credit) amortization	44		45		(29)		(28)		(111)		(111)
Actuarial loss (gain) amortization	5,852		5,447		120		53		(315)		(341)
Net periodic benefit cost (benefit)	$	10,767	$	10,030	$	393	$	201	$	(51)	$	(32)
	Six Months Ended February 28,
	Qualified Pension Benefits				Nonqualified Pension Benefits				Other Benefits
	2022		2021		2022		2021		2022		2021
Components of net periodic benefit costs:	(Dollars in thousands)
Service cost	$	23,138	$	22,614	$	463	$	217	$	498	$	593
Interest cost	8,584		8,281		141		136		252		246
Expected return on assets	(21,979)		(21,821)		—		—		—		—
Prior service cost (credit) amortization	87		89		(57)		(57)		(223)		(223)
Actuarial loss (gain) amortization	11,703		10,895		239		106		(630)		(682)
Net periodic benefit cost (benefit)	$	21,533	$	20,058	$	786	$	402	$	(103)	$	(66)