We have a defined benefit pension plan (pension plan) that covers certain U.S. citizen employees and other employees who are permanent residents of the United States. The accrual of benefits was discontinued once the pension plan was frozen during 2010. We did not contribute to the pension plan during the quarters ended March 31, 2020 and 2019, and we are not required to contribute to the pension plan during the remaining quarters of calendar year 2020; however, we may, at our discretion, make contributions to the pension plan in order to manage our plan expenses.

We also support a non-contributory and non-qualified defined benefit supplemental executive retirement plan (supplemental plan) which was closed to new participants during 2010, that provided pension benefits to certain employees in excess of those allowed under our tax-qualified pension plan. We contributed $0.4 million during the three months ended March 31, 2020. We contributed immaterial amounts to the supplemental plan during the three months ended March 31, 2019. We expect to contribute $1.2 million to the supplemental plan during the remainder of 2020. Our obligations under the supplemental plan were $21.5 million and $21.4 million as of March 31, 2020 and December 31, 2019, respectively, and are included in “accrued costs and expenses” and “other liabilities” on the consolidated balance sheet.

We also have defined benefit pension plans that cover certain Norwegian citizen employees and other employees who are permanent residents of Norway. Benefits are based on years of service and employee compensation. Our contributions to the Norwegian defined benefit pension plans during the three months ended March 31, 2020 and 2019, respectively, were immaterial and we expect that any contributions during the remainder of calendar year 2020 will be immaterial. Substantially, all of our Norwegian employees were transferred from our defined benefit pension plans into a defined contribution plan during the first quarter of 2020.

The net periodic benefit cost for our defined benefit pension plans and supplemental plan (referred to collectively as “Pension Benefits”) is comprised of the following components:

		Three Months			Three Months
		Ended			Ended
(In thousands)		March 31, 2020			March 31, 2019
Pension Benefits:
Service cost	$		40		$	56
Interest cost			225			932
Expected return on plan assets			(36	)		(563	)
Administrative expenses			23			10
Settlement loss			508			—
Amortization of net actuarial losses			(44	)		72
Net periodic pension cost	$		716		$	507