Derivative Financial Instruments - Narrative (Details) MWh in Millions, $ in Millions	1 Months Ended	3 Months Ended
	Jun. 30, 2012 MWh	Mar. 31, 2023 USD ($)	Jan. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (639)		$ (638)
Corporate, Non-Segment [Member] | Notes Payable to Banks [Member]
Derivative [Line Items]
Debt Instrument, Face Amount		2,500
Corporate, Non-Segment [Member] | Notes515Mar2028 | Notes Payable to Banks [Member]
Derivative [Line Items]
Debt Instrument, Face Amount		1,000
Commonwealth Edison Co [Member]
Derivative [Line Items]
Long-term Purchase Commitment, Minimum Energy Volume Required | MWh	1.3
PECO Energy Co [Member]
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		$ 39
Estimated Percent of Gas Purchases Being Hedged		10.00%
Baltimore Gas and Electric Company [Member]
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		$ 73
Baltimore Gas and Electric Company [Member] | Maximum [Member]
Derivative [Line Items]
Estimated Percent of Gas Purchases Being Hedged		20.00%
Baltimore Gas and Electric Company [Member] | Minimum [Member]
Derivative [Line Items]
Estimated Percent of Gas Purchases Being Hedged		10.00%
Delmarva Power and Light Company [Member]
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		$ 14
Estimated Percent of Gas Purchases Being Hedged		50.00%
Interest Rate Swap [Member] | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		$ 130	$ 230	1,270
Derivative, Cash Received on Hedge		10
Interest Rate Cap | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount		1,000		1,850
InterestRateSwapNotional5YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		65	115
InterestRateSwapNotional10YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		65	115
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 4,100	3,600	500
InterestRateSwapNotionalTerminated | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount			1,500
Accumulated Other Comprehensive Income (Loss), Net of Tax			$ 7
InterestRateCap18month | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount				1,000
InterestRateCapNotional6month | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount				$ 850