Regulatory Matters - Schedule of Pending Rate Cases (Details) - USD ($)								3 Months Ended		9 Months Ended
	Sep. 29, 2023	Aug. 21, 2023	May 16, 2023	Apr. 21, 2023	Apr. 13, 2023	Feb. 17, 2023	Jan. 17, 2023	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)							$ 1,487,000,000
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 520,000,000
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | Minimum [Member]
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities, Requested Equity Capital Structure, Percentage							50.58%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | Maximum [Member]
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities, Requested Equity Capital Structure, Percentage							51.19%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage							10.50%
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 968,000,000
Public Utilities, Requested Equity Capital Structure, Percentage							7.40%
Public Utilities, Requested Rate Increase (Decrease), Proposed Revenue Requirement Phase-In							$ 339,000,000
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage							10.55%
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 181,000,000
Public Utilities, Requested Equity Capital Structure, Percentage							7.47%
Public Utilities, Requested Rate Increase (Decrease), Proposed Revenue Requirement Phase-In							$ 52,000,000
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage							10.60%
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 163,000,000
Public Utilities, Requested Equity Capital Structure, Percentage							7.58%
Public Utilities, Requested Rate Increase (Decrease), Proposed Revenue Requirement Phase-In							$ 75,000,000
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2027
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage							10.65%
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 175,000,000
Public Utilities, Requested Equity Capital Structure, Percentage							7.65%
Commonwealth Edison Co | Illinois 2023 Electric Distribution Base Rate Case | 2028
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount							$ 215,000,000
Commonwealth Edison Co | Illinois 2023 Electric Distribution Reconciliation Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities Requested Rate Increase (Decrease), Prior Year Annual Reconciliation				$ 247,000,000
Requested Return on Equity, Percentage				8.91%
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 313,000,000
Requested Return on Equity, Percentage						10.40%
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 85,000,000
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						103,000,000
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						125,000,000
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 289,000,000
Requested Return on Equity, Percentage						10.40%
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2024
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 158,000,000
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2025
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						77,000,000
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Base Rate Case | 2026
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 54,000,000
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Reconciliation Rate Case | 2021
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)									$ 11,000,000
Baltimore Gas and Electric Company | Maryland 2023 Electric Distribution Reconciliation Rate Case | 2022
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)								$ 44,000,000
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Reconciliation Rate Case | 2021
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)									$ 7,000,000
Baltimore Gas and Electric Company | Maryland 2023 Gas Distribution Reconciliation Rate Case | 2022
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)								$ 15,000,000		$ 25,000,000
Potomac Electric Power Company | District of Columbia 2023 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)					$ 191,000,000
Requested Return on Equity, Percentage					10.50%
Potomac Electric Power Company | District of Columbia 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)					$ 117,000,000
Potomac Electric Power Company | District of Columbia 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)					37,000,000
Potomac Electric Power Company | District of Columbia 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)					$ 37,000,000
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			$ 214,000,000
Requested Return on Equity, Percentage			10.50%
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2024
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			$ 74,000,000
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2025
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			60,000,000
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2026
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			60,000,000
Potomac Electric Power Company | Pepco Maryland 2023 Electric Distribution Base Rate Case | 2027
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			$ 20,000,000
Delmarva Power and Light Company | Delaware DE 2022 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease), Amended	$ 39,000,000
Requested Return on Equity, Percentage	10.50%
Atlantic City Electric Company | New Jersey 2023 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease), Amended		$ 92,000,000
Requested Return on Equity, Percentage		10.50%