Employee Benefit Plans

The components of net period benefit cost for the three months ended March 31, 2018 and 2017 are as follows:



	Three Months Ended March 31, 2018
	Retirement Income Plan			National Service-Related Pension Plan			Other Post-Retirement Benefits		Superannuation			Total
Components of net periodic benefit cost:	(In thousands)
Service cost	$	8		$	19		$	—	$	58		$	85
Interest cost	354			300			5		27			686
Expected return on plan assets	(512		)	(342		)	—		(45		)	(899		)
Amortization of net loss	311			179			—		—			490
Amortization of prior service cost	—			—			—		8			8
Net pension benefit cost	$	161		$	156		$	5	$	48		$	370



	Three Months Ended March 31, 2017
	Retirement Income Plan			National Service-Related Pension Plan			Other Post-Retirement Benefits		Superannuation			Total
Components of net periodic benefit cost:	(In thousands)
Service cost	$	16		$	126		$	—	$	58		$	200
Interest cost	396			314			6		30			746
Expected return on plan assets	(439		)	(294		)	—		(43		)	(776		)
Amortization of net loss	472			204			—		—			676
Amortization of prior service cost	—			53			—		—			53
Effect of settlement	173			59			—		—			232
Net pension benefit cost	$	618		$	462		$	6	$	45		$	1,131

The Company expects to contribute $3.2 million to all plans in 2018.

Multi-Employer Plans

The Company contributes to a number of multi-employer benefit plans under the terms of collective bargaining agreements that cover union-represented employees. These plans generally provide for retirement, death, and/or termination benefits for eligible employees within the applicable collective bargaining units, based on specific eligibility/participation requirements, vesting periods, and benefit formulas. Details on multi-employer benefit plans can be found in the Annual Report on Form 10-K for the year ended December 31, 2017.

The New England Teamsters & Trucking Industry Multi-Employer Fund (Fund) is grossly underfunded in accordance with Employee Retirement Income Security Act of 1974 (ERISA) funding standards and, therefore, ERISA required the Fund to develop a Rehabilitation Plan, creating a new fund that minimizes the pension withdrawal liability. As a result, current employers participating in the Fund were given the opportunity to exit the Fund and convert to a new fund. The Company's portion of the unfunded liability, estimated at $13.7 million, will be repaid in equal monthly installments of approximately $38 thousand over 30 years, interest free. Under the relevant U.S. GAAP standard, a participating employer withdrawing from a multi-employer plan should account for a loss contingency equal to the present value of the withdrawal liability, and amortize difference between such present value and the estimated unfunded liability through interest expense over the repayment period.