Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2016

Entity Information [Line Items]

Schedule of Net Periodic Benefit Cost / (Income)

The net periodic benefit cost of the pension and postretirement benefit plans for the three and nine months ended September 30, 2016 and 2015 was:

Net Periodic Benefit Cost	Pension
	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2016			2015			2016			2015
Service cost	$	1.4		$	1.7		$	4.2		$	5.3
Interest cost	3.7			4.4			11.1			13.0
Expected return on plan assets	(5.7		)	(5.7		)	(17.1		)	(17.0		)
Amortization of unrecognized:
Prior service cost	0.4			0.5			1.4			1.5
Actuarial loss	1.1			1.5			3.2			4.4
Net periodic benefit cost	$	0.9		$	2.4		$	2.8		$	7.2

Net Periodic Benefit Cost	Postretirement
	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2016			2015			2016			2015
Service cost	$	—		$	0.1		$	0.1		$	0.1
Interest cost	0.2			0.2			0.4			0.5
Expected return on plan assets	(0.1		)	(0.1		)	(0.1		)	(0.1		)
Amortization of unrecognized:
Prior service cost	—			—			—			—
Actuarial gain	(0.1		)	(0.1		)	(0.4		)	(0.3		)
Net periodic benefit cost	$	—		$	0.1		$	—		$	0.2

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Benefit payments and Medicare Part D reimbursements, which reflect future service, are estimated to be paid as follows:

$ in millions	Pension		Postretirement
2016	$	6.2	$	0.4
2017	25.2		1.6
2018	25.8		1.5
2019	26.3		1.4
2020	26.7		1.4
2021 - 2025	134.8		5.7

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 and postretirement benefit plans for the three and nine months ended September 30, 2016 and 2015 was:

Net Periodic Benefit Cost	Pension
	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2016			2015			2016			2015
Service cost	$	1.4		$	1.8		$	4.2		$	5.3
Interest cost	3.7			4.2			11.1			12.8
Expected return on plan assets	(5.7		)	(5.6		)	(17.1		)	(16.8		)
Amortization of unrecognized:
Prior service cost	0.8			0.9			2.3			2.5
Actuarial loss	1.8			2.4			5.4			7.2
Net periodic benefit cost	$	2.0		$	3.7		$	5.9		$	11.0

Net Periodic Benefit Cost	Postretirement
	Three months ended						Nine months ended
	September 30,						September 30,
$ in millions	2016			2015			2016			2015
Service cost	$	—		$	0.1		$	0.1		$	0.1
Interest cost	0.1			0.1			0.4			0.5
Expected return on plan assets	(0.1		)	(0.1		)	(0.1		)	(0.1		)
Amortization of unrecognized:
Prior service cost	0.1			0.1			0.1			0.1
Actuarial gain	(0.1		)	(0.2		)	(0.5		)	(0.5		)
Net periodic benefit cost	$	—		$	—		$	—		$	0.1

Estimated Future Benefit Payments and Medicare Part D Reimbursements

Benefit payments and Medicare Part D reimbursements, which reflect future service, are estimated to be paid as follows:

$ in millions	Pension		Postretirement
2016	$	6.2	$	0.4
2017	25.2		1.6
2018	25.8		1.5
2019	26.3		1.4
2020	26.7		1.4
2021 - 2025	134.8		5.7