Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2024

Entity Information [Line Items]

Fair Value, Assets Measured on Recurring Basis

The fair value of assets at December 31, 2024 and 2023 and the respective category within the fair value hierarchy for DPL was determined as follows:

$ in millions	Fair Value at December 31, 2024								Fair Value at December 31, 2023
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Master trust assets
Money market funds	$	0.4	$	—	$	—	$	0.4	$	0.6	$	—	$	—	$	0.6
Mutual funds	7.6		—		—		7.6		7.2		—		—		7.2
Total assets	$	8.0	$	—	$	—	$	8.0	$	7.8	$	—	$	—	$	7.8

Fair Value Disclosure of Asset and Liability Not Measured at Fair Value

The following table presents the carrying amount, fair value, and fair value hierarchy of our financial liabilities that are not measured at fair value in the Consolidated Balance Sheets as of the periods indicated, but for which fair value is disclosed:

	Carrying Amount		Fair Value at December 31, 2024								Carrying Amount		Fair Value at December 31, 2023
$ in millions			Level 1		Level 2		Level 3		Total				Level 1		Level 2		Level 3		Total
Liabilities
Long-term debt	$	1,840.0	$	—	$	1,692.4	$	16.6	$	1,709.0	$	1,837.6	$	—	$	1,706.2	$	16.8	$	1,723.0

THE DAYTON POWER AND LIGHT COMPANY [Member]

Entity Information [Line Items]

Fair Value, Assets Measured on Recurring Basis

The fair value of assets at December 31, 2024 and 2023 and the respective category within the fair value hierarchy for AES Ohio was determined as follows:

$ in millions	Fair Value at December 31, 2024								Fair Value at December 31, 2023
	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Money market funds	$	0.4	$	—	$	—	$	0.4	$	0.6	$	—	$	—	$	0.6
Mutual funds	7.6		—		—		7.6		7.2		—		—		7.2
Total assets	$	8.0	$	—	$	—	$	8.0	$	7.8	$	—	$	—	$	7.8