Regulatory Matters (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021
Regulatory Assets, Noncurrent	$ 129.8	$ 176.8
RSC Rider	79.0
COVID-19 Deferral [Member]
Regulatory Assets, Noncurrent	0.9
THE DAYTON POWER AND LIGHT COMPANY [Member]
Regulatory Assets, Noncurrent	129.8	$ 176.8
RSC Rider	79.0
THE DAYTON POWER AND LIGHT COMPANY [Member] \| COVID-19 Deferral [Member]
Regulatory Assets, Noncurrent	$ 0.9

Carrying amount as of the balance sheet date of capitalized costs of regulated entities that are not expected to be recovered through revenue sources within one year or the normal operating cycle if longer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 980
-SubTopic 340
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

Name:	us-gaap_RegulatoryAssetsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant