19.Pension and Postretirement Benefit Obligations

Pension Plans

There are two Company-sponsored pension plans. The primary Company-sponsored pension plan was frozen as of June 30, 2006 and no benefits accrued to participants after this date. The second Company-sponsored pension plan (the “Bargaining Plan”) is for certain employees under collective bargaining agreements. Benefits under the Bargaining Plan are determined in accordance with negotiated formulas for the respective participants. Contributions to the plans are based on actuarially determined amounts and are limited to the amounts currently deductible for income tax purposes.

The components of net periodic pension cost were as follows:

	Third Quarter						First Three Quarters
(in thousands)	2018			2017			2018			2017
Service cost	$	1,412		$	150		$	4,237		$	450
Interest cost		2,856			2,978			8,568			8,936
Expected return on plan assets		(3,853	)		(3,399	)		(11,557	)		(10,197	)
Recognized net actuarial loss		934			807			2,800			2,421
Amortization of prior service cost		6			7			18			21
Net periodic pension cost	$	1,355		$	543		$	4,066		$	1,631

The Company contributed $20.0 million to the two Company sponsored pension plans during the third quarter of 2018 and does not anticipate making additional contributions during the fourth quarter of 2018.

Postretirement Benefits

The Company provides postretirement benefits for a portion of its current employees. The Company recognizes the cost of postretirement benefits, which consist principally of medical benefits, during covered employees’ periods of active service. The Company does not pre-fund these benefits and has the right to modify or terminate certain of these benefits in the future.

The components of net periodic postretirement benefit cost were as follows:

	Third Quarter						First Three Quarters
(in thousands)	2018			2017			2018			2017
Service cost	$	502		$	572		$	1,507		$	1,716
Interest cost		696			910			2,088			2,732
Recognized net actuarial loss		499			648			1,497			1,944
Amortization of prior service cost		(462	)		(745	)		(1,386	)		(2,237	)
Net periodic postretirement benefit cost	$	1,235		$	1,385		$	3,706		$	4,155

Multi-Employer Benefits

Certain employees of the Company whose employment is covered under collective bargaining agreements participate in a multi-employer pension plan, the Employers-Teamsters Local Union Nos. 175 and 505 Pension Fund (the “Teamsters Plan”). The Company makes monthly contributions to the Teamsters Plan on behalf of such employees. The collective bargaining agreements covering the Teamsters Plan expire at various times by April 2020. The Company expects these agreements will be re-negotiated.

The risks of participating in the Teamsters Plan are different from single-employer plans as contributed assets are pooled and may be used to provide benefits to employees of other participating employers. If a participating employer stops contributing to the Teamsters Plan, the unfunded obligations of the Teamsters Plan may be borne by the remaining participating employers. If the Company chooses to stop participating in the Teamsters Plan, the Company could be required to pay the Teamsters Plan a withdrawal liability based on the underfunded status of the Teamsters Plan. The Company does not anticipate withdrawing from the Teamsters Plan.

In 2015, the Company increased its contribution rates to the Teamsters Plan, with additional increases occurring annually, as part of a rehabilitation plan, which was incorporated into the renewal of collective bargaining agreements with the unions effective April 28, 2014 and adopted by the Company as a rehabilitation plan effective January 1, 2015. This was a result of the Teamsters Plan being certified by its actuary as being in “critical” status for the plan year beginning January 1, 2013.