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 six months ended February 28, 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 February 28 are as follows:	(Dollars in thousands)
Service cost	$	9,920		$	11,692		$	137	$	344		$	236		$	227
Interest cost	5,991			3,812			178		70			227			39
Expected return on assets	(12,049		)	(12,101		)	—		—			—			—
Prior service cost (credit) amortization	360			368			7		(47		)	(142		)	(253		)
Actuarial (gain) loss amortization	4,511			6,650			16		100			(306		)	(283		)
Net periodic benefit cost	$	8,733		$	10,421		$	338	$	467		$	15		$	(270	)
Components of net periodic benefit costs for the six months ended February 28 are as follows:
Service cost	$	19,839		$	21,075		$	274	$	603		$	472		$	580
Interest cost	11,992			11,504			356		422			454			466
Expected return on assets	(24,089		)	(24,115		)	—		—			—			—
Prior service cost (credit) amortization	719			770			15		10			(283		)	(283		)
Actuarial (gain) loss amortization	11,399			11,415			30		273			(612		)	(399		)
Net periodic benefit cost	$	19,860		$	20,649		$	675	$	1,308		$	31		$	364

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 six months ended February 28, 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.