Employee Benefit Plans

The components of net period benefit cost for the three and six months ended June 30, 2018 and 2017 are as follows:



	Three Months Ended June 30, 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		$	20		$	—	$	73		$	101
Interest cost	354			300			5		26			685
Expected return on plan assets	(512		)	(342		)	—		(44		)	(898		)
Amortization of net loss	312			179			—		—			491
Amortization of prior service cost	—			—			—		7			7
Net pension benefit cost	$	162		$	157		$	5	$	62		$	386



	Three Months Ended June 30, 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	$	17		$	126		$	—	$	58		$	201
Interest cost	395			314			5		29			743
Expected return on plan assets	(439		)	(294		)	—		(43		)	(776		)
Amortization of net loss	301			145			—		—			446
Amortization of prior service cost	—			53			—		—			53
Effect of settlement	104			59			—		—			163
Net pension benefit cost	$	378		$	403		$	5	$	44		$	830



	Six Months Ended June 30, 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	$	15		$	39		$	—	$	131		$	185
Interest cost	709			600			10		53			1,372
Expected return on plan assets	(1,024		)	(685		)	—		(89		)	(1,798		)
Amortization of net loss	623			357			—		—			980
Amortization of prior service cost	—			—			—		18			18
Net pension benefit cost	$	323		$	311		$	10	$	113		$	757



	Six Months Ended June 30, 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	$	33		$	252		$	—	$	116		$	401
Interest cost	791			628			11		59			1,489
Expected return on plan assets	(878		)	(588		)	—		(86		)	(1,552		)
Amortization of net loss	774			348			—		—			1,122
Amortization of prior service cost	—			106			—		—			106
Effect of settlement	277			118			—		—			395
Net pension benefit cost	$	997		$	864		$	11	$	89		$	1,961

The Company expects to contribute an aggregate of $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 took the option to exit the Fund and convert to the new fund. The Company's portion of the unfunded liability, estimated at $13.7 million, will be repaid in equal monthly installments of approximately $38,000 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.