11.	Pension and Employee Benefit Plans

We sponsor a non-contributory defined benefit pension plan for certain union employees. The plan is funded in accordance with the funding requirements of the Employee Retirement Income Security Act of 1974.

We also sponsor a postretirement health care plan for office employees retired before January 1, 1990. The plan allowed retirees who attained the age of 65 to elect the type of coverage desired.

We present service cost within cost of sales and selling and administrative expenses depending on where the relevant employees compensation costs are recorded, and we present other components of net periodic benefit cost (gain) within other expense, net on the Condensed Consolidated Statements of Operations.

Retirement and health care plan expense is based on valuations performed by plan actuaries as of the beginning of each fiscal year. The components of the expense consisted of the following:

(Table only in thousands)	Three Months Ended September 30,						Nine Months Ended September 30,
	2018			2017			2018			2017
Pension plan:
Service cost	$	—		$	101		$	—		$	315
Interest cost		298			329			893			986
Expected return on plan assets		(378	)		(431	)		(1,134	)		(1,292	)
Amortization of net actuarial loss		59			57			178			170
Net periodic benefit cost (gain)	$	(21	)	$	56		$	(63	)	$	179
Health care plan:
Interest cost	$	1		$	1		$	2		$	2
Amortization of loss		2			2			7			6
Net periodic benefit cost	$	3		$	3		$	9		$	8

We made contributions to our defined benefit plans during the nine months ended September 30, 2018 and 2017 totaling $0.6 million and $1.6 million, respectively. We anticipate $0.2 million and $24,000 of further contributions to fund the pension plan and the retiree health care plan, respectively, during the remainder of 2018. The unfunded liability of the plans of $9.1 million and $9.6 million as of September 30, 2018 and December 31, 2017, respectively, is included in Other liabilities on our Condensed Consolidated Balance Sheets.