Regulatory Matters (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 14, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Regulatory assets earning a return		$ 3.5
Regulatory Assets, Noncurrent		129.8	$ 176.8
Regulatory Assets, Current		39.2	24.5
Regulatory Assets		169.0	201.3
Regulatory Liability, Noncurrent		198.7	229.3
Regulatory Liability, Current		40.4	14.6
Regulatory Liabilities		239.1	243.9
TCJA Yearly Refund to Customers Per DRO		4.0
DRO Vegetation Management Cost Baseline		15.7			$ 10.7
DRO Vegetation Management Cost Deferral Cap		4.6
RSC Rider		$ 79.0
Return on Equity SEET Threshold		9.85%
Cash Contribution from Parent Company			150.0	$ 150.0
Equity Contribution from Parent		$ 0.0	132.5	98.0
TFR True-Up Liability		18.2
TFR True-up Liability, Current		12.8
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%
Unrecovered OVEC Charges [Member]		28.9
Vegetation Management and Other [Member]
Regulatory Assets, Noncurrent		$ 23.0
Undercollections to be collected [Member]
Regulatory Assets Type of Recovery		A/B
Regulatory Assets, Current		$ 38.7	23.9
Amounts being recovered through base rates [Member]
Regulatory Assets Type of Recovery		B
Regulatory Assets, Current		$ 0.5	0.6
Pension Costs [Member]
Regulatory Assets Type of Recovery		B
Regulatory Assets, Noncurrent		$ 64.2	76.2
Deferred Regulatory Compliance Costs [Member]
Regulatory Assets Type of Recovery		B
Regulatory Assets, Noncurrent		$ 6.4	6.3
Ccem Smart Grid And Advanced Metering Infrastructure Cost [Member]
Regulatory Assets Type of Recovery		B
Regulatory Assets, Noncurrent		$ 2.3	5.2
Loss on Reacquired Debt [Member]
Regulatory Assets Type of Recovery		B
Regulatory Assets, Noncurrent		$ 2.0	4.3
Storm Costs [Member]
Regulatory Assets Type of Recovery		A
Regulatory Assets, Noncurrent		$ 8.7	15.2
Vegetation Management [Member]
Regulatory Assets Type of Recovery		A/B
Regulatory Assets, Noncurrent			18.7
Decoupling Deferral and Other [Member] [Domain]
Regulatory Assets Type of Recovery		C
Regulatory Assets, Noncurrent		$ 13.8	13.8
Uncollectible and Other [Member] [Domain]
Regulatory Assets Type of Recovery		C
Regulatory Assets, Noncurrent		$ 7.5	6.4
COVID-19 Deferral [Member]
Regulatory Assets, Noncurrent		0.9
Writeoff of COVID-19 Deferral		$ 0.9
Storm Costs
Regulatory Assets Type of Recovery		B
Regulatory Assets, Noncurrent		$ 1.9	1.8
Unrecovered OVEC Charges - Regulatory Asset
Regulatory Assets Type of Recovery		C
Regulatory Assets, Noncurrent		$ 0.0	28.9
Subsidiaries [Member]
Regulatory assets earning a return		3.5
Regulatory Assets, Noncurrent		129.8	176.8
Regulatory Assets, Current		39.2	24.5
Regulatory Assets		169.0	201.3
Regulatory Liability, Noncurrent		198.7	229.3
Regulatory Liability, Current		40.4	14.6
Regulatory Liabilities		239.1	243.9
TCJA Yearly Refund to Customers Per DRO		4.0
DRO Vegetation Management Cost Baseline		15.7			$ 10.7
DRO Vegetation Management Cost Deferral Cap		4.6
RSC Rider		$ 79.0
Return on Equity SEET Threshold		9.85%
Equity Contribution from Parent		$ 0.0	150.0	$ 150.0
TFR True-Up Liability		18.2
TFR True-up Liability, Current		12.8
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%
Unrecovered OVEC Charges [Member]		28.9
Subsidiaries [Member] | Vegetation Management and Other [Member]
Regulatory Assets, Noncurrent		$ 23.0
Subsidiaries [Member] | Undercollections to be collected [Member]
Regulatory Assets Type of Recovery		A/B
Regulatory Current Asset, End Date for Recovery		2023
Regulatory Assets, Current		$ 38.7	23.9
Subsidiaries [Member] | Amounts being recovered through base rates [Member]
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		2023
Regulatory Assets, Current		$ 0.5	0.6
Subsidiaries [Member] | Pension Costs [Member]
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		Ongoing
Regulatory Assets, Noncurrent		$ 64.2	76.2
Subsidiaries [Member] | Deferred Regulatory Compliance Costs [Member]
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		Undetermined
Regulatory Assets, Noncurrent		$ 6.4	6.3
Subsidiaries [Member] | Ccem Smart Grid And Advanced Metering Infrastructure Cost [Member]
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		2025
Regulatory Assets, Noncurrent		$ 2.3	5.2
Subsidiaries [Member] | Loss on Reacquired Debt [Member]
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		Various
Regulatory Assets, Noncurrent		$ 2.0	4.3
Subsidiaries [Member] | Storm Costs [Member]
Regulatory Assets Type of Recovery		A
Regulatory Current Asset, End Date for Recovery		Undetermined
Regulatory Assets, Noncurrent		$ 8.7	15.2
Subsidiaries [Member] | Vegetation Management [Member]
Regulatory Assets Type of Recovery		A/B
Regulatory Current Asset, End Date for Recovery		Undetermined
Regulatory Assets, Noncurrent			18.7
Subsidiaries [Member] | Decoupling Deferral and Other [Member] [Domain]
Regulatory Assets Type of Recovery		C
Regulatory Current Asset, End Date for Recovery		Undetermined
Regulatory Assets, Noncurrent		$ 13.8	13.8
Subsidiaries [Member] | Uncollectible and Other [Member] [Domain]
Regulatory Assets Type of Recovery		C
Regulatory Current Asset, End Date for Recovery		Undetermined
Regulatory Assets, Noncurrent		$ 7.5	6.4
Subsidiaries [Member] | COVID-19 Deferral [Member]
Regulatory Assets, Noncurrent		0.9
Writeoff of COVID-19 Deferral		$ 0.9
Subsidiaries [Member] | Storm Costs
Regulatory Assets Type of Recovery		B
Regulatory Current Asset, End Date for Recovery		Undetermined
Subsidiaries [Member] | Unrecovered OVEC Charges - Regulatory Asset
Regulatory Assets Type of Recovery		C
Regulatory Current Asset, End Date for Recovery
Regulatory Assets, Noncurrent		$ 0.0	28.9
Postretirement Benefit Costs [Member]
Regulatory Liabilities Type of Recovery		B
Regulatory Liability, Noncurrent		$ 3.3	2.8
Postretirement Benefit Costs [Member] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery		B
Regulatory Liability, Amortization Through		Ongoing
Regulatory Liability, Noncurrent		$ 3.3	2.8
PJM transmission enhancement settlement repayment amount [Member]
Regulatory Liabilities Type of Recovery		A
Regulatory Liability, Noncurrent		$ 3.5	5.1
PJM transmission enhancement settlement repayment amount [Member] | Subsidiaries [Member]
Regulatory Current Asset, End Date for Recovery		2025
Regulatory Liabilities Type of Recovery		A
Regulatory Liability, Noncurrent		$ 3.5	5.1
Deferred Income Tax Charge [Member]
Regulatory Liability, Noncurrent		$ 45.2	57.5
Deferred Income Tax Charge [Member] | Subsidiaries [Member]
Regulatory Liability, Amortization Through		Various
Regulatory Liability, Noncurrent		$ 45.2	57.5
TCJA Regulatory Liability [Member] [Domain]
Regulatory Liabilities Type of Recovery		B
Regulatory Liability, Noncurrent		$ 4.5	6.5
TCJA Regulatory Liability [Member] [Domain] | Subsidiaries [Member]
Regulatory Liabilities Type of Recovery		B
Regulatory Liability, Amortization Through		Ongoing
Regulatory Liability, Noncurrent		$ 4.5	6.5
Removal Costs [Member]
Regulatory Liability, Noncurrent		136.8	145.2
Removal Costs [Member] | Subsidiaries [Member]
Regulatory Liability, Noncurrent		$ 136.8	145.2
Overcollection of costs to be refunded [Member]
Regulatory Liabilities Type of Recovery		A/B
Regulatory Liability, Noncurrent		$ 27.6	14.2
Overcollection of costs to be refunded [Member] | Subsidiaries [Member]
Regulatory Current Asset, End Date for Recovery		2023
Regulatory Liabilities Type of Recovery		A/B
Regulatory Liability, Noncurrent		$ 27.6	14.2
Transmission Formula Rate Credits
Regulatory Liabilities Type of Recovery		A
Regulatory Liability, Noncurrent		$ 12.8	0.4
Transmission Formula Rate Credits | Subsidiaries [Member]
Regulatory Current Asset, End Date for Recovery		2023
Regulatory Liabilities Type of Recovery		A
Regulatory Liability, Noncurrent		$ 12.8	0.4
Transmission Formula Rate Credits, Noncurrent
Regulatory Liability, Noncurrent		$ 5.4	12.2
Transmission Formula Rate Credits, Noncurrent | Subsidiaries [Member]
Regulatory Current Asset, End Date for Recovery		2024
Regulatory Liabilities Type of Recovery		A
Regulatory Liability, Noncurrent		$ 5.4	$ 12.2