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 the components of net periodic benefit cost (gain) within “Other income (expense), net” on the Condensed Consolidated Statements of Income.

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:

	Three months ended March 31,
(table only in thousands)	2020			2019
Pension plan:
Interest cost	$	258		$	326
Expected return on plan assets		(350	)		(313	)
Amortization of net actuarial loss		65			65
Net periodic benefit (gain) cost	$	(27	)	$	78
Health care plan:
Interest cost	$	1		$	1
Amortization of loss		2			2
Net periodic benefit cost	$	3		$	3

We made contributions to our defined benefit plans of approximately $0.1 million during the three-months ended March 31, 2020 and 2019, respectively. For the remainder of 2020, we have elected to defer further contributions to fund the pension plan and the retiree health care plan until January 2021. The unfunded liability of the plans of $8.7 million and $8.9 million as of March 31, 2020 and December 31, 2019, respectively, is included in “Other liabilities” on our Condensed Consolidated Balance Sheets.