Changes in the plans' benefit obligations and funded status are as follows:



							Postretirement and Other Benefits
	Pension Benefits						Postretirement and Other Benefits
(dollars in millions)	2018			2017			2018			2017
Change in benefit obligation:
Benefit obligation at January 1,	$	489.2		$	505.6		$	98.6		$	82.6
Hawaiian Telcom opening balance sheet adjustment	184.1			—			51.2			—
Service cost	—			—			0.6			0.2
Interest cost	20.0			19.4			4.2			3.2
Actuarial (gain) loss	(39.9		)	28.1			(20.3		)	7.6
Benefits paid	(43.0		)	(38.6		)	(13.1		)	(11.6		)
Retiree drug subsidy received	—			—			0.3			0.2
Transfer of special death benefit	—			(14.0		)	—			14.0
Settlements	(3.6		)	(11.3		)	—			—
Other	—			—			2.2			2.4
Benefit obligation at December 31,	$	606.8		$	489.2		$	123.7		$	98.6

Change in plan assets:
Fair value of plan assets at January 1,	$	392.1		$	372.3		$	7.5		$	8.7
Hawaiian Telcom opening balance sheet adjustment	163.0			—			—			—
Actual (loss) return on plan assets	(37.7		)	64.8			0.3			0.2
Employer contributions	11.6			4.6			10.8			10.0
Retiree drug subsidy received	—			—			0.3			0.2
Benefits paid	(43.0		)	(38.6		)	(13.1		)	(11.6		)
Settlements	(3.6		)	(11.0		)	—			—
Fair value of plan assets at December 31,	482.4			392.1			5.8			7.5
Unfunded status	$	(124.4	)	$	(97.1	)	$	(117.9	)	$	(91.1	)

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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