Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Other Paid-In Capital [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]	THE DAYTON POWER AND LIGHT COMPANY [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Other Comprehensive Income (Loss), Net of Tax	$ (5.8)						$ (1.6)
Balance at Dec. 31, 2018	(471.7)	$ 0.0	$ 2,370.5	$ 2.2	$ (2,844.4)		445.3	$ 0.4	$ 711.8	$ (35.3)	$ (231.6)
Balance (in shares) at Dec. 31, 2018		1						41,172,173
Net comprehensive income/ (loss)	99.6						123.3
Net loss	105.4						124.9
Common stock dividends							(95.0)		(95.0)
Equity Contribution from Parent	0.0						0.0
Other	0.2		0.2				0.2		(0.2)		0.4
Balance at Dec. 31, 2019	(371.9)	$ 0.0	2,370.7	(3.6)	(2,739.0)		473.4	$ 0.4	617.0	(36.9)	(107.1)
Balance (in shares) at Dec. 31, 2019		1						41,172,173
Other Comprehensive Income (Loss), Net of Tax	(8.7)					$ (0.9)	(5.2)					$ 0.4
Net comprehensive income/ (loss)	(9.7)						45.9
Net loss	(1.0)						51.1
Common stock dividends							52.7		(52.7)
Equity Contribution from Parent	(98.0)		(98.0)				(150.0)		150.0
Other	(0.1)		(0.1)				(0.1)		(0.1)		0.0
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
Non-cash capital contribution	98.0
Other Comprehensive Income (Loss), Net of Tax	7.5					$ (0.8)	10.3					$ 0.0
Net comprehensive income/ (loss)	29.6						57.4
Net loss	22.1						47.1
Common stock dividends							(42.0)		(42.0)
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