Derivative Financial Instruments - Narrative (Details) - USD ($) $ in Millions	1 Months Ended
	Feb. 29, 2024	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax		$ (712)	$ (726)
Corporate, Non-Segment | Notes Payable to Banks
Derivative [Line Items]
Derivative, Notional Amount	$ 1,700
Derivative, Cash Received on Hedge	30
PECO Energy Co
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		27
Baltimore Gas and Electric Company
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		47
Delmarva Power and Light Company
Derivative [Line Items]
Incremental Collateral For Loss Of Investment Grade Credit Rating		12
InterestRateSwapNotionalTerminated | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount	1,300
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 33	23
InterestRateSwapNotional5YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		145	655
InterestRateSwapNotional10YR | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		145	655
Interest Rate Swap | Cash Flow Hedging
Derivative [Line Items]
Derivative, Notional Amount		$ 290	1,310
Interest Rate Cap | Economic Hedges
Derivative [Line Items]
Derivative, Notional Amount			1,000
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge [Member]
Derivative [Line Items]
Total mark-to-market derivative liabilities			(22)
Constant Maturity Treasury Interest Rate Swaps | Not Designated as Hedging Instrument, Economic Hedge [Member] | 2023
Derivative [Line Items]
Derivative, Notional Amount			$ 4,875