Consolidated Statements of Comprehensive Income/(Loss) (Parenthetical) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income tax (expense)/benefit on prior service cost related to pension and postretirement activity	$ 0.1	$ 0.0	$ 0.0
Income tax (expense)/benefit on net loss related to pension and postretirement activity	0.3	(0.7)	(1.8)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Income tax (expense)/benefit on prior service cost related to pension and postretirement activity	0.1	0.0	0.0
Income tax (expense)/benefit on net loss related to pension and postretirement activity	$ 0.4	$ (0.6)	$ (1.8)

Amount of tax expense (benefit) for (increase) decrease in value of benefit obligation for change in actuarial assumptions and increase (decrease) in value of plan assets from experience different from that assumed of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 12
-SubTopic 10
-Topic 220
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482790/220-10-45-12

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Balance Type:	debit
Period Type:	duration