Derivative Financial Instruments - Narrative (Details) MWh in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2012 MWh	Feb. 14, 2023 USD ($)	Jan. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Derivative [Line Items]
Derivative, Notional Amount				$ 3,434	$ 3,481
Accumulated other comprehensive loss, net				(638)	(2,750)
Other				1,155	766
Commonwealth Edison Co [Member]
Derivative [Line Items]
Long-term Purchase Commitment, Minimum Energy Volume Required | MWh	1.3
Other				191	133
PECO Energy Co [Member]
Derivative [Line Items]
Other				32	35
Incremental collateral for loss of investment grade credit rating				71
Baltimore Gas and Electric Company [Member]
Derivative [Line Items]
Other				55	48
Incremental collateral for loss of investment grade credit rating				119
Pepco Holdings LLC [Member]
Derivative [Line Items]
Other				330	171
Potomac Electric Power Company [Member]
Derivative [Line Items]
Other				93	55
Delmarva Power & Light Company [Member]
Derivative [Line Items]
Other				136	59
Incremental collateral for loss of investment grade credit rating				15
Atlantic City Electric Company [Member]
Derivative [Line Items]
Other				58	12
InterestRateSwapNotional5YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount				635
InterestRateSwapNotional5YR | Cash Flow Hedging | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount			$ 115
InterestRateSwapNotional10YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount				635
InterestRateSwapNotional10YR | Cash Flow Hedging | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount			115
Interest Rate Swap [Member] | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount				1,270	0
Accumulated other comprehensive loss, net				2
Interest Rate Swap [Member] | Cash Flow Hedging | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount			230
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
Interest Rate Cap | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount				1,850	0
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Derivative, Notional Amount				500	0
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge [Member] | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 1,500
Constant Maturity Treasury Interest Rate Swaps Through Report Date | Not Designated as Hedging Instrument, Economic Hedge [Member] | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount		$ 2,000
Commodity Contract [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				297
Commodity Contract [Member] | Commonwealth Edison Co [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				77	41
Commodity Contract [Member] | Baltimore Gas and Electric Company [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				23
Commodity Contract [Member] | Pepco Holdings LLC [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				197
Commodity Contract [Member] | Potomac Electric Power Company [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				26
Commodity Contract [Member] | Delmarva Power & Light Company [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				121	$ 43
Commodity Contract [Member] | Atlantic City Electric Company [Member] | External Counterparties | Collateral [Member]
Derivative [Line Items]
Other				$ 50
InterestRateSwap-Through Report Date | Cash Flow Hedging | Subsequent Event [Member]
Derivative [Line Items]
Derivative, Notional Amount			$ 1,500