Employees

Postretirement Benefits

The components of net periodic benefit cost related to our benefit plans consisted of the following:



Components of net periodic benefit cost:	Three Months Ended June 30, 2018			Six Months Ended June 30, 2018
Service cost	$	0.2		$	0.4
Interest cost	1.2			2.4
Expected return on plan assets	(1.8		)	(3.6		)
Recognition due to settlement	—			(0.1		)
Net periodic benefit	$	(0.4	)	$	(0.9	)

The service cost component of net periodic benefit is included as part of general and administrative expenses in the accompanying condensed consolidated statements of income. The other components of net periodic benefit are included as part of other non-operating income, net. During the three months ended March 31, 2018, we completely settled the supplemental retirement income plan of the retail segment, and we had a partial settlement of Alon's executive non-qualified restoration plan.

Our estimated contributions to our pension plans during 2018 have not changed significantly from amounts previously disclosed in the notes to the consolidated financial statements for the year ended December 31, 2017. For the three and six months ended June 30, 2018, we made no contributions to our funded qualified pension plan, but made $0.1 million and $4.2 million of contributions related to payments to participants in our unfunded pension plans.