Benefit Plans

We have various pension and other defined benefit and defined contribution plans, in which substantially all employees may participate. We also have non-qualified supplemental executive and Board retirement plans.

Components of net periodic benefit costs for the three and nine months ended May 31, 2018, and 2017, are as follows:



	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

Employer Contributions

Total contributions to be made during fiscal 2018 will depend primarily on market returns on the pension plan assets and minimum funding level requirements. During the nine months ended May 31, 2018, we made no contributions to the pension plans. At this time, we do not anticipate being required to make a contribution for our benefit plans in fiscal 2018.