Income Taxes (Components of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Depreciation / property basis	$ (166.4)	$ (160.5)
Income taxes recoverable	13.6	14.4
Deferred Tax Liabilities, Regulatory Assets and Liabilities	(20.6)	(21.0)
Investment tax credit	0.6	0.6
Compensation and employee benefits	(3.4)	(1.7)
Intangibles	(0.4)	(0.4)
Long-term debt	(1.5)	(1.3)
Other	(9.8)	(7.3)
Net non-current liabilities	(187.9)	(177.2)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Income Taxes [Line Items]
Depreciation / property basis	(167.7)	(161.7)
Income taxes recoverable	13.6	14.4
Deferred Tax Liabilities, Regulatory Assets and Liabilities	(21.4)	(21.7)
Investment tax credit	0.5	0.5
Compensation and employee benefits	3.4	0.1
Other	(5.0)	(3.5)
Net non-current liabilities	$ (183.4)	$ (172.1)

Deferred Tax Liabilities, Income Taxes Recoverable

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Deferred Tax Liabilities Long-term Debt

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible tax credit carryforwards, classified as other.

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Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from compensation and benefits costs.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting and classified as noncurrent.

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