10. EMPLOYEE BENEFIT PLANS

Pension and Other Postemployment Benefit Plans

The components of the net periodic cost for pension benefits, including the Company's Pension Equalization Plan, and OPEB costs (principally health care and life insurance) for employees and covered dependents were as follows:



	Pension												OPEB
	Three Months Ended						Six Months Ended						Three Months Ended						Six Months Ended
	March 31,						March 31,						March 31,						March 31,
(Thousands)	2018			2017			2018			2017			2018			2017			2018			2017
Service cost	$	2,034		$	2,087		$	4,069		$	4,174		$	1,151		$	1,095		$	2,303		$	2,190
Interest cost	2,624			2,442			5,247			4,885			1,591			1,387			3,182			2,773
Expected return on plan assets	(4,909		)	(4,828		)	(9,819		)	(9,656		)	(1,338		)	(1,191		)	(2,676		)	(2,383		)
Recognized actuarial loss	1,885			2,206			3,769			4,413			1,165			1,092			2,330			2,185
Prior service cost amortization	26			28			53			55			(91		)	(91		)	(182		)	(182		)
Net periodic benefit cost	$	1,660		$	1,935		$	3,319		$	3,871		$	2,478		$	2,292		$	4,957		$	4,583

The Company does not expect to be required to make additional contributions to fund the pension plans during fiscal 2018 or 2019 based on current actuarial assumptions; however, funding requirements are uncertain and can depend significantly on changes in actuarial assumptions, returns on plan assets and changes in the demographics of eligible employees and covered dependents. In addition, as in the past, the Company may elect to make contributions in excess of the minimum required amount to the plans. There were no discretionary contributions made during the six months ended March 31, 2018.