Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2018

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The net periodic benefit cost of the pension benefit plans for the three and nine months ended September 30, 2018 and 2017 was:

	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2018			2017			2018			2017
Service cost	$	1.5		$	1.5		$	4.5		$	4.3
Interest cost	3.4			3.5			10.3			10.6
Expected return on plan assets	(5.3		)	(5.7		)	(15.9		)	(17.1		)
Plan curtailment (a)	—			—			—			4.1
Amortization of unrecognized:
Prior service cost	0.3			0.2			0.8			0.8
Actuarial loss	1.6			1.3			4.8			4.0
Net periodic benefit cost	$	1.5		$	0.8		$	4.5		$	6.7

(a) As a result of the decision to retire certain of DPL's coal-fired plants, we recognized a plan curtailment of $4.1 million in the first quarter of 2017.

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Benefit payments, which reflect future service, are estimated to be paid as follows:

$ in millions
Estimated balance to be paid during	Pension
2018	$	7.1
2019	$	28.2
2020	$	27.9
2021	$	27.6
2022	$	27.3
2023 - 2027	$	131.3

THE DAYTON POWER AND LIGHT COMPANY [Member]

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The net periodic benefit cost of the pension benefit plans for the three and nine months ended September 30, 2018 and 2017 was:

	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2018			2017			2018			2017
Service cost	$	1.5		$	1.5		$	4.5		$	4.3
Interest cost	3.4			3.5			10.3			10.6
Expected return on plan assets	(5.3		)	(5.7		)	(15.9		)	(17.1		)
Plan curtailment (a)	—			—			—			5.6
Amortization of unrecognized:
Prior service cost	0.4			0.3			1.1			1.1
Actuarial loss	2.4			2.1			7.1			6.6
Net periodic benefit cost	$	2.4		$	1.7		$	7.1		$	11.1

(a) As a result of the decision to retire certain of DPL's coal-fired plants, we recognized a plan curtailment of $5.6 million in the first quarter of 2017.

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Benefit payments, which reflect future service, are estimated to be paid as follows:

$ in millions
Estimated balance to be paid during	Pension
2018	$	7.1
2019	$	28.2
2020	$	27.9
2021	$	27.6
2022	$	27.3
2023 - 2027	$	131.3