Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Jan. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Derivative, Notional Amount	$ 3,351		$ 3,434
Accumulated other comprehensive loss, net	(726)		(638)
Corporate, Non-Segment
Derivative [Line Items]
Accumulated other comprehensive loss, net	(726)		(638)
Corporate, Non-Segment | Notes Payable to Banks
Derivative [Line Items]
Debt instrument, face amount	2,500
PECO Energy Co
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating	25
Baltimore Gas and Electric Company
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating	61
Delmarva Power & Light Company
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating	10
InterestRateSwapNotional5YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount	655	$ 115	635
InterestRateSwapNotional10YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount	655	115	635
Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount	1,310	230	1,270
Derivative, Cash Received on Hedge	10
Accumulated other comprehensive loss, net	10
Accumulated Other Comprehensive Income Gain, Net of Tax			2
InterestRateSwapTerminated | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		1,500
Accumulated other comprehensive loss, net		$ 7
InterestRateCap18month | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Derivative, Notional Amount			1,000
InterestRateCapNotional6month | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Derivative, Notional Amount			850
Interest Rate Cap | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Derivative, Notional Amount	1,000		1,850
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge
Derivative [Line Items]
Derivative, Notional Amount	0		$ 500
Derivative Liability	22
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge | 2023
Derivative [Line Items]
Derivative, Notional Amount	$ 4,875