Regulatory Matters (Details) - USD ($) $ in Millions				12 Months Ended			60 Months Ended
	Jul. 01, 2025	Apr. 10, 2023	Dec. 14, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Sep. 30, 2028
Regulatory assets earning a return				$ 9.3
Regulatory Assets, Noncurrent				155.7	$ 129.8
Regulatory Assets, Current				56.6	39.2
Regulatory Assets				212.3	169.0
Regulatory Liability, Noncurrent				182.1	198.7
Regulatory Liability, Current				18.0	40.4
Regulatory Liabilities				200.1	239.1
DRO Vegetation Management Cost Baseline				20.0
DRO Vegetation Management Cost Deferral Cap				7.5
RSC Rider				$ 79.0
Return on Equity SEET Threshold				9.85%
Cash Contribution from Parent Company				$ 260.0		$ 150.0
Equity Contribution from Parent				239.0	0.0	132.5
Revenue Increase - Distribution Rate Case			$ 75.6
Return on Equity - Distribution Rate Case			9.999%
Cost of Long-term Debt - Distribution Rate Case			4.40%
Rate Base - Distribution Rate Case			$ 783.5
Capital Structure - Equity - Distribution Rate Case			53.87%
Capital Structure - Long-term Debt - Distribution Rate Case			46.13%
Maximum Regulatory compliance cost to be accrued							$ 4.0
Maximum CIS Replacement cost deferral				8.8
Vegetation Management and Other [Member]
Regulatory Assets, Noncurrent				$ 19.9
Undercollections to be collected [Member]
Regulatory Assets Type of Recovery				A/B
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Assets, Current				$ 51.7	38.7
Amounts being recovered through base rates [Member]
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Assets, Current				$ 1.7	0.0
Pension Costs [Member]
Regulatory Assets Type of Recovery				A/B
Regulatory Current Asset, End Date for Recovery				Ongoing
Regulatory Assets, Noncurrent				$ 62.6	64.2
Deferred Regulatory Compliance Costs [Member]
Regulatory Assets Type of Recovery				A
Regulatory Current Asset, End Date for Recovery				2028
Regulatory Assets, Noncurrent				$ 45.0	6.4
Ccem Smart Grid And Advanced Metering Infrastructure Cost [Member]
Regulatory Assets Type of Recovery				B/C
Regulatory Current Asset, End Date for Recovery				Ongoing
Regulatory Assets, Noncurrent				$ 3.2	2.3
Loss on Reacquired Debt [Member]
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				Ongoing
Regulatory Assets, Noncurrent				$ 1.1	2.0
Storm Costs [Member]
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				Ongoing
Regulatory Assets, Noncurrent				$ 2.2	8.7
Vegetation Management [Member]
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2028
Regulatory Assets, Noncurrent					21.9
Decoupling Deferral and Other [Member] [Domain]
Regulatory Assets Type of Recovery				A
Regulatory Current Asset, End Date for Recovery				2028
Regulatory Assets, Noncurrent				$ 0.0	13.8
Uncollectible and Other [Member] [Domain]
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2028
Regulatory Assets, Noncurrent				$ 6.3	7.5
Storm Costs
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2028
Regulatory Assets, Noncurrent				$ 1.5	1.9
Energy Efficiency
Regulatory Assets Type of Recovery				D
Regulatory Current Asset, End Date for Recovery				Undetermined
Regulatory Assets, Noncurrent				$ 4.1	0.0
Transmission Formula Rate Debits
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2025
Regulatory Assets, Noncurrent				$ 6.7	0.0
CIS Replacement Costs
Regulatory Assets Type of Recovery				D
Regulatory Current Asset, End Date for Recovery				Undetermined
Regulatory Assets, Noncurrent				$ 3.1	1.1
Vegetation management costs recovered in base rates
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Assets, Current				$ 2.7	0.0
Rate case expenses recovered through base rates
Regulatory Assets Type of Recovery				B
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Assets, Current				$ 0.5	0.5
Subsidiaries [Member]
Regulatory assets earning a return				9.3
Regulatory Assets, Noncurrent				155.7	129.8
Regulatory Assets, Current				56.6	39.2
Regulatory Assets				212.3	169.0
Regulatory Liability, Noncurrent				182.1	198.7
Regulatory Liability, Current				18.0	40.4
Regulatory Liabilities				200.1	239.1
TCJA Yearly Refund to Customers Per DRO				4.0
DRO Vegetation Management Cost Baseline				20.0
DRO Vegetation Management Cost Deferral Cap				7.5
RSC Rider				$ 79.0
Return on Equity SEET Threshold				9.85%
Equity Contribution from Parent				$ 260.0	0.0	$ 150.0
Revenue Increase - Distribution Rate Case			$ 75.6
Return on Equity - Distribution Rate Case			9.999%
Cost of Long-term Debt - Distribution Rate Case			4.40%
Rate Base - Distribution Rate Case			$ 783.5
Capital Structure - Equity - Distribution Rate Case			53.87%
Capital Structure - Long-term Debt - Distribution Rate Case			46.13%
Return on Equity - ESP 4		9.999%
Recovery - ESP 4		$ 66.0
Deferral of Purchased Power Costs - ESP 4				28.3
Deferral of Carrying Costs - ESP 4				10.7
Maximum CIS Replacement cost deferral				8.8
Subsidiaries [Member] | Vegetation Management and Other [Member]
Regulatory Assets, Noncurrent				$ 19.9
Subsidiaries [Member] | Undercollections to be collected [Member]
Regulatory Assets Type of Recovery				A/B
Regulatory Assets, Current				$ 51.7	38.7
Subsidiaries [Member] | Amounts being recovered through base rates [Member]
Regulatory Assets Type of Recovery				B
Regulatory Assets, Current				$ 1.7	0.0
Subsidiaries [Member] | Pension Costs [Member]
Regulatory Assets Type of Recovery				A/B
Regulatory Assets, Noncurrent				$ 62.6	64.2
Subsidiaries [Member] | Deferred Regulatory Compliance Costs [Member]
Regulatory Assets Type of Recovery				A
Regulatory Assets, Noncurrent				$ 45.0	6.4
Subsidiaries [Member] | Ccem Smart Grid And Advanced Metering Infrastructure Cost [Member]
Regulatory Assets Type of Recovery				B/C
Regulatory Assets, Noncurrent				$ 3.2	2.3
Subsidiaries [Member] | Loss on Reacquired Debt [Member]
Regulatory Assets Type of Recovery				B
Regulatory Assets, Noncurrent				$ 1.1	2.0
Subsidiaries [Member] | Storm Costs [Member]
Regulatory Assets Type of Recovery				B
Regulatory Assets, Noncurrent				$ 2.2	8.7
Subsidiaries [Member] | Vegetation Management [Member]
Regulatory Assets Type of Recovery				B
Regulatory Assets, Noncurrent					21.9
Subsidiaries [Member] | Decoupling Deferral and Other [Member] [Domain]
Regulatory Assets Type of Recovery				A
Regulatory Assets, Noncurrent				$ 0.0	13.8
Subsidiaries [Member] | Uncollectible and Other [Member] [Domain]
Regulatory Assets Type of Recovery				B
Regulatory Assets, Noncurrent				$ 6.3	7.5
Subsidiaries [Member] | Storm Costs
Regulatory Assets Type of Recovery				B
Subsidiaries [Member] | Energy Efficiency
Regulatory Assets Type of Recovery				D
Regulatory Assets, Noncurrent				$ 4.1	0.0
Subsidiaries [Member] | Transmission Formula Rate Debits
Regulatory Assets Type of Recovery				B
Regulatory Assets, Noncurrent				$ 6.7	0.0
Subsidiaries [Member] | CIS Replacement Costs
Regulatory Assets Type of Recovery				D
Regulatory Assets, Noncurrent				$ 3.1	1.1
Subsidiaries [Member] | Vegetation management costs recovered in base rates
Regulatory Assets Type of Recovery				B
Regulatory Assets, Current				$ 2.7	0.0
Subsidiaries [Member] | Rate case expenses recovered through base rates
Regulatory Assets Type of Recovery				B
Regulatory Assets, Current				$ 0.5	0.5
Postretirement Benefit Costs [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Amortization Through				Ongoing
Regulatory Liability, Noncurrent				$ 2.6	3.3
Postretirement Benefit Costs [Member] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 2.6	3.3
PJM transmission enhancement settlement repayment amount [Member]
Regulatory Current Asset, End Date for Recovery				2025
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 1.7	3.5
PJM transmission enhancement settlement repayment amount [Member] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 1.7	3.5
Deferred Income Tax Charge [Member]
Regulatory Liability, Amortization Through				Ongoing
Regulatory Liability, Noncurrent				$ 42.6	45.2
Deferred Income Tax Charge [Member] | Subsidiaries [Member]
Regulatory Liability, Noncurrent				$ 42.6	45.2
TCJA Regulatory Liability [Member] [Domain]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Amortization Through				Ongoing
Regulatory Liability, Noncurrent				$ 1.0	4.5
TCJA Regulatory Liability [Member] [Domain] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 1.0	4.5
Removal Costs [Member]
Regulatory Liability, Noncurrent				134.2	136.8
Removal Costs [Member] | Subsidiaries [Member]
Regulatory Liability, Noncurrent				$ 134.2	136.8
Overcollection of costs to be refunded [Member]
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Liabilities Type of Recovery				A/B
Regulatory Liability, Noncurrent				$ 14.7	27.6
Overcollection of costs to be refunded [Member] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				A/B
Regulatory Liability, Noncurrent				$ 14.7	27.6
Transmission Formula Rate Credits
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 3.3	12.8
Transmission Formula Rate Credits | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 3.3	12.8
Transmission Formula Rate Credits, Noncurrent
Regulatory Current Asset, End Date for Recovery				2024
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 0.0	5.4
Transmission Formula Rate Credits, Noncurrent | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery				B
Regulatory Liability, Noncurrent				$ 0.0	$ 5.4
Forecast [Member]
TCJA Yearly Refund to Customers Per DRO				4.0
Estimated Smart Grid Phase 2 costs	$ 683.0
Forecast [Member] | Subsidiaries [Member]
TCJA Yearly Refund to Customers Per DRO				$ 4.0
Estimated Smart Grid Phase 2 costs	$ 683.0