The following tables provide information with respect to the net periodic costs of our pension and post-retirement medical benefit plans included in continuing operations.

	Three months ended March 31
In thousands	2020			2019
Pension Benefits
Service cost	$	44		$	484
Interest cost		301			3,450
Expected return on plan assets		—			(3,696	)
Amortization of prior service cost		12			34
Amortization of unrecognized loss		160			775
Total net periodic benefit cost	$	517		$	1,047

Other Benefits
Service cost	$	7		$	9
Interest cost		46			84
Amortization of prior service credit		(116	)		(2	)
Amortization of actuarial gain		(209	)		(173	)
Total net periodic benefit credit	$	(272	)	$	(82	)

During 2019, our qualified pension plan was terminated, and all plan liabilities were settled by either a lump sum distribution or assumed by a third-party in exchange for a transfer of assets from the pension plan trust fund. For active participants, the pension benefit was replaced with an enhance defined contribution plan, or 401(k), to which we contributed a percent of eligible compensation. Currently we contribute 10%.

As of March 31, 2020, $51.1 million of assets remained in the pension trust and was included in cash and cash equivalents in the accompanying condensed consolidated balance sheet. We expect to complete the reversion of the qualified pension plan assets in the second quarter of 2020, after a portion of the assets are transferred to a trust fund to be used to make contributions over the next seven years to the 401(k) plan and satisfying excise tax obligations, approximately $33 million is expected to revert to us and will be available for general corporate purposes.

In December 2019, our Board of Directors approved the freezing of benefit accruals in the non-qualified pension plan for active participants effective December 31, 2019. As of January 1, 2020, each active participant’s frozen non-qualified pension benefit was transferred to a newly approved Deferred Compensation Plan non-qualified benefit plan and earns interest credits going forward. The Deferred Compensation Plan also provides for employer contributions and, in the future, the Plan may provide for elective employee deferrals. Under the Deferred Compensation Plan, participants are eligible to receive annual Company contributions that such

participants would have received under the P. H. Glatfelter 401(k) Savings Plan but for certain limitations imposed by the Internal Revenue Code on 401(k) plan contributions (“Company Contributions”).