Derivative Financial Instruments - Summary of Counterparty Collateral (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Other current liabilities	$ 512	$ 519
Commonwealth Edison Co
Derivative [Line Items]
Other current liabilities	270	219
PECO Energy Co
Derivative [Line Items]
Other current liabilities	80	59
Baltimore Gas and Electric Company
Derivative [Line Items]
Other current liabilities	39	32
Potomac Electric Power Company
Derivative [Line Items]
Other current liabilities	51	61
Delmarva Power & Light Company
Derivative [Line Items]
Other current liabilities	22	21
Atlantic City Electric Company
Derivative [Line Items]
Other current liabilities	10	12
External Counterparties | Commodity Contract | Collateral
Derivative [Line Items]
Other current liabilities	181	148
External Counterparties | Commodity Contract | Collateral | Commonwealth Edison Co
Derivative [Line Items]
Other current liabilities	176	146
External Counterparties | Commodity Contract | Collateral | PECO Energy Co
Derivative [Line Items]
Other current liabilities	0	0
External Counterparties | Commodity Contract | Collateral | Baltimore Gas and Electric Company
Derivative [Line Items]
Other current liabilities	1	1
External Counterparties | Commodity Contract | Collateral | Pepco Holdings LLC
Derivative [Line Items]
Other current liabilities	4	1
External Counterparties | Commodity Contract | Collateral | Potomac Electric Power Company
Derivative [Line Items]
Other current liabilities	1	1
External Counterparties | Commodity Contract | Collateral | Delmarva Power & Light Company
Derivative [Line Items]
Other current liabilities	2	0
External Counterparties | Commodity Contract | Collateral | Atlantic City Electric Company
Derivative [Line Items]
Other current liabilities	$ 0	$ 0