Derivative Financial Instruments - Summary of Counterparty Collateral (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	$ 536	$ 512
External Counterparties \| Commodity Contract [Member] \| Collateral [Member]
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	196	181
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Commonwealth Edison Co
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	173	176
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| PECO Energy Co
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	6	0
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Baltimore Gas and Electric Company
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	5	1
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Pepco Holdings LLC
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	12	4
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Potomac Electric Power Company
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	3	1
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Delmarva Power and Light Company
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	5	2
External Counterparties \| Commodity Contract [Member] \| Collateral [Member] \| Atlantic City Electric Company
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Other	$ 5	$ 0