Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Other Paid-In Capital [Member]	Reclassification out of Accumulated Other Comprehensive Income [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Retained Earnings [Member]	Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]	THE DAYTON POWER AND LIGHT COMPANY [Member]	THE DAYTON POWER AND LIGHT COMPANY [Member] Common Stock [Member]	THE DAYTON POWER AND LIGHT COMPANY [Member] Other Paid-In Capital [Member]	THE DAYTON POWER AND LIGHT COMPANY [Member] Accumulated Other Comprehensive Income/(Loss) [Member]	THE DAYTON POWER AND LIGHT COMPANY [Member] Retained Earnings [Member]
Other Comprehensive Income (Loss), Net of Tax	$ 7.5							$ 10.3
Balance at Dec. 31, 2020	(283.5)	$ 0.0	$ 2,468.8		$ (12.3)	$ (2,740.0)		616.7	$ 0.4	$ 714.4	$ (42.1)	$ (56.0)
Balance (in shares) at Dec. 31, 2020		1							41,172,173
Net loss	22.1							47.1
Common stock dividends								(42.0)		(42.0)		0.0
Equity Contribution from Parent	(132.5)		(132.5)					(150.0)		150.0
Other								(0.1)		(0.1)		0.0
Balance at Dec. 31, 2021	(121.4)	$ 0.0	2,601.3		(4.8)	(2,717.9)		782.2	$ 0.4	822.5	(31.8)	(8.9)
Balance (in shares) at Dec. 31, 2021		1							41,172,173
Non-cash capital contribution	132.5
Other Comprehensive Income (Loss), Net of Tax	2.4						$ (0.8)	5.0
Net loss	(4.7)							18.9
Common stock dividends								64.0		(49.0)		(15.0)
Equity Contribution from Parent	0.0							0.0
Other								0.3		(0.1)		0.4
Balance at Dec. 31, 2022	(123.7)	$ 0.0	2,601.3		(2.4)	(2,722.6)		741.8	$ 0.4	773.6	(26.8)	(5.4)
Balance (in shares) at Dec. 31, 2022		1							41,172,173
Other Comprehensive Income (Loss), Net of Tax	(2.2)						$ (0.8)	(1.1)
Net loss	35.7							61.4
Common stock dividends								(83.0)		(56.3)		(26.7)
Equity Contribution from Parent	(239.0)		(239.0)					(260.0)		260.0
Other	(0.1)		(0.1)	$ 0.0		0.0		(0.1)		(0.1)		0.0
Balance at Dec. 31, 2023	$ 148.9	$ 0.0	$ 2,840.4		$ (4.6)	$ (2,686.9)		$ 979.2	$ 0.4	$ 977.4	$ (27.9)	$ 29.3
Balance (in shares) at Dec. 31, 2023		1