Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2020

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 six months ended June 30, 2020 and 2019 was:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2020		2019		2020		2019
Service cost	$	1.0	$	0.9	$	1.9	$	1.8
Interest cost	2.9		3.8		5.9		7.5
Expected return on plan assets	(4.7)		(5.0)		(9.4)		(10.0)
Amortization of unrecognized:
Prior service cost	0.2		0.3		0.5		0.6
Actuarial loss	1.6		1.0		3.1		2.1
Net periodic benefit cost	$	1.0	$	1.0	$	2.0	$	2.0

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 six months ended June 30, 2020 and 2019 was:

	Three months ended				Six months ended
	June 30,				June 30,
$ in millions	2020		2019		2020		2019
Service cost	$	1.0	$	0.9	$	1.9	$	1.8
Interest cost	2.9		3.8		5.9		7.5
Expected return on plan assets	(4.7)		(5.0)		(9.4)		(10.0)
Amortization of unrecognized:
Prior service cost	0.4		0.4		0.7		0.9
Actuarial loss	2.1		1.8		4.3		3.5
Net periodic benefit cost	$	1.7	$	1.9	$	3.4	$	3.7