Fair Value (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Inputs and Valuation Techniques

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 Condensed Consolidated Balance Sheets as of the periods indicated, but for which fair value is disclosed:

	Carrying Amount		Fair value as of March 31, 2023								Carrying Amount		Fair value as of December 31, 2022
$ in millions			Level 1		Level 2		Level 3		Total				Level 1		Level 2		Level 3		Total
Liabilities
Long-term debt	$	1,536.7	$	—	$	1,392.0	$	17.0	$	1,409.0	$	1,535.9	$	—	$	1,376.4	$	17.0	$	1,393.4

Fair Value of Assets and Liabilities Measured on Recurring Basis

The fair value of assets and liabilities as of March 31, 2023 and December 31, 2022 measured on a recurring basis and the respective category within the fair value hierarchy for DPL is as follows:

	Fair value as of March 31, 2023								Fair value as of December 31, 2022
$ in millions	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Master Trust assets
Money market funds	$	0.3	$	—	$	—	$	0.3	$	0.5	$	—	$	—	$	0.5
Mutual funds	7.1		—		—		7.1		7.0		—		—		7.0
Total assets	$	7.4	$	—	$	—	$	7.4	$	7.5	$	—	$	—	$	7.5

Subsidiaries [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Inputs and Valuation Techniques

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 Condensed Balance Sheets as of the periods indicated, but for which fair value is disclosed:

	Carrying Amount		Fair value as of March 31, 2023							Carrying Amount		Fair value as of December 31, 2022
$ in millions			Level 1		Level 2		Level 3	Total				Level 1		Level 2		Level 3		Total
Liabilities
Long-term debt	$	713.0	$	—	$	623.3	17.0	$	640.3	$	712.7	$	—	$	610.9	$	17.0	$	627.9

Fair Value of Assets and Liabilities Measured on Recurring Basis

The fair value of assets and liabilities as of March 31, 2023 and December 31, 2022 measured on a recurring basis and the respective category within the fair value hierarchy for AES Ohio is as follows:

	Fair value as of March 31, 2023								Fair value as of December 31, 2022
$ in millions	Level 1		Level 2		Level 3		Total		Level 1		Level 2		Level 3		Total
Assets
Master Trust assets
Money market funds	$	0.3	$	—	$	—	$	0.3	$	0.5	$	—	$	—	$	0.5
Mutual funds	7.1		—		—		7.1		7.0		—		—		7.0
Total assets	$	7.4	$	—	$	—	$	7.4	$	7.5	$	—	$	—	$	7.5