Regulatory Matters - Schedule of Completed Rate Cases (Details) $ in Millions															9 Months Ended	48 Months Ended
	Jun. 10, 2024 USD ($)	Apr. 18, 2024 USD ($)	Feb. 23, 2024 USD ($)	Dec. 14, 2023 USD ($)	Nov. 30, 2023 USD ($)	Nov. 17, 2023 USD ($)	Sep. 29, 2023 USD ($)	Aug. 21, 2023 USD ($)	Apr. 21, 2023 USD ($)	Feb. 17, 2023 USD ($)	Jan. 17, 2023 USD ($)	Dec. 14, 2022 USD ($)	May 19, 2022 USD ($)	Feb. 03, 2022	Sep. 30, 2024 USD ($)	Dec. 31, 2027 USD ($)
Commonwealth Edison Co
Regulatory Matters Completed Rate Cases [Line Items]
Basis points for ComEd's Revenue Requirement														580
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)											$ 1,487
Approved Revenue Requirement Increase (Decrease)				$ 501
Approved Return on Equity, Percentage				8.905%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | Forecast [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Approved Debt Capital Structure, Percentage																50.00%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2023 | Forecast [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)																$ (986)
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				$ 451
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				14
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				6
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2027
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				30
Commonwealth Edison Co | Illinois 2023 Electric Distribution Order on Rehearing
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)											$ 838
Approved Revenue Requirement Increase (Decrease)		$ 810
Approved Return on Equity, Percentage		8.905%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Order on Rehearing | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)		$ 150
Commonwealth Edison Co | Illinois 2023 Electric Distribution Order on Rehearing | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)		186
Commonwealth Edison Co | Illinois 2023 Electric Distribution Order on Rehearing | 2026
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)		221
Commonwealth Edison Co | Illinois 2023 Electric Distribution Order on Rehearing | 2027
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)		253
Commonwealth Edison Co | Illinois 2023 Electric Distribution Reconciliation Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities Requested Rate Increase (Decrease), Prior Year Annual Reconciliation									$ 247
Approved Revenue Requirement Increase (Decrease)					$ 259
Approved Return on Equity, Percentage					8.91%
Public Utilities, Approved Equity Capital Structure, Percentage					6.48%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Reconciliation Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Basis points for ComEd's Revenue Requirement					580
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)										$ 313
Approved Revenue Requirement Increase (Decrease)				$ 179
Approved Return on Equity, Percentage				9.50%
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				$ 41
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				113
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				25
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)										$ 289
Approved Revenue Requirement Increase (Decrease)				$ 229
Approved Return on Equity, Percentage				9.45%
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				$ 126
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				62
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2026
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)				$ 41
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Reconciliation Rate Case | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															$ 13
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Reconciliation Rate Case | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															39
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Reconciliation Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															79
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Reconciliation Rate Case | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															7
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Reconciliation Rate Case | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															15
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Reconciliation Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)															$ 73
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount			$ 111
Approved Revenue Requirement Increase (Decrease)	$ 45
Approved Return on Equity, Percentage	9.50%
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)	$ 45
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	80
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	51
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2027
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	14
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Reconciliation Rate Case | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)	1
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Reconciliation Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)	7
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Reconciliation Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)	$ 31
Delmarva Power and Light Company | Maryland 2022 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)													$ 38
Approved Revenue Requirement Increase (Decrease)												$ 29
Approved Return on Equity, Percentage												9.60%
Delmarva Power and Light Company | Maryland 2022 Electric Distribution Base Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												$ 17
Delmarva Power and Light Company | Maryland 2022 Electric Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												6
Delmarva Power and Light Company | Maryland 2022 Electric Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												$ 6
Delmarva Power and Light Company | Delaware 2022 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount							$ 39
Approved Revenue Requirement Increase (Decrease)		$ 28
Approved Return on Equity, Percentage		9.60%
Delmarva Power and Light Company | Delaware 2022 Electric Distribution Base Rate Case | Minimum [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease) Annual Reconciliation		$ 5
Delmarva Power and Light Company | Delaware 2022 Electric Distribution Base Rate Case | Maximum [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease) Annual Reconciliation		$ 15
Atlantic City Electric Company | New Jersey 2023 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount								$ 92
Approved Revenue Requirement Increase (Decrease)						$ 45
Approved Return on Equity, Percentage						9.60%
Atlantic City Electric Company | New Jersey 2023 Electric Distribution Base Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)						$ 36
Atlantic City Electric Company | New Jersey 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)						$ 9