Employee Benefit Plans

Net periodic cost (benefit) of the Defined Benefit Pension, Post-Retirement Medical, and Supplemental Executive Retirement plans included in general insurance expenses in the accompanying condensed consolidated statements of income includes the following components:



	Three Months Ended March 31,
	Defined Benefit Pension Plan						Post-Retirement Medical Plan						Supplemental Executive Retirement Plan						Total
	2018			2017			2018			2017			2018			2017			2018			2017
Components of net periodic cost (benefit):
Service cost	$	—		$	(2,067	)	$	376		$	357		$	—		$	(4	)	$	376		$	(1,714	)
Interest cost	5,709			6,121			172			188			339			405			6,220			6,714
Expected return on plan assets	(5,331		)	(5,118		)	—			—			—			—			(5,331		)	(5,118		)
Amortization of unrecognized prior service costs (benefits)	—			—			(69		)	(52		)	81			125			12			73
Amortization of losses (gains) from earlier periods	584			2,199			(5		)	(113		)	(11		)	(13		)	568			2,073
Net periodic cost (benefit)	$	962		$	1,135		$	474		$	380		$	409		$	513		$	1,845		$	2,028

The Company expects to make payments of approximately $329 with respect to its Post-Retirement Medical Plan and $2,398 with respect to its Supplemental Executive Retirement Plan during the year ended December 31, 2018. The Company does not expect to make contributions to its Defined Benefit Pension Plan during the year ended December 31, 2018. A December 31 measurement date is used for the employee benefit plans.

The following table summarizes payments made to the Post-Retirement Medical Plan and the Supplemental Executive Retirement Plan:



	Three Months Ended March 31,
	2018		2017
Payments to the Post-Retirement Medical Plan	$	82	$	169
Payments to the Supplemental Executive Retirement Plan	599		834