Benefit Plans Schedule of Net Benefit Costs (Tables)

9 Months Ended

May 31, 2018

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs of Assumptions Used

	Qualified Pension Benefits						Non-Qualified Pension Benefits				Other Benefits
	2018			2017			2018		2017		2018			2017
Components of net periodic benefit costs for the three months ended May 31 are as follows:	(Dollars in thousands)
Service cost	$	9,920		$	10,537		$	137	$	302	$	236		$	290
Interest cost	5,997			5,753			177		210		227			232
Expected return on assets	(12,044		)	(12,058		)	—		—		—			—
Prior service cost (credit) amortization	360			385			7		4		(142		)	(141		)
Actuarial (gain) loss amortization	4,905			5,708			16		136		(306		)	(199		)
Net periodic benefit cost	$	9,138		$	10,325		$	337	$	652	$	15		$	182
Components of net periodic benefit costs for the nine months ended May 31 are as follows:
Service cost	$	29,758		$	31,612		$	411	$	905	$	707		$	870
Interest cost	17,988			17,257			533		632		681			698
Expected return on assets	(36,133		)	(36,173		)	—		—		—			—
Prior service cost (credit) amortization	1,078			1,155			23		14		(424		)	(424		)
Actuarial (gain) loss amortization	16,304			17,123			46		409		(918		)	(598		)
Net periodic benefit cost	$	28,995		$	30,974		$	1,013	$	1,960	$	46		$	546