Regulatory Matters - Schedule of Completed Rate Cases (Details) $ in Millions	Dec. 14, 2022 USD ($)	Nov. 17, 2022 USD ($)	Oct. 27, 2022 USD ($)	May 19, 2022 USD ($)	Apr. 15, 2022 USD ($)	Mar. 31, 2022 USD ($)	Feb. 23, 2022	Feb. 03, 2022	Dec. 22, 2021	Jun. 28, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 16, 2020 USD ($)	Sep. 11, 2020 USD ($)
Commonwealth Edison Co [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Basis points for ComEd's Revenue Requirement								580
Commonwealth Edison Co [Member] | Illinois 2022 Electric Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)					$ 199
Approved Revenue Requirement Increase (Decrease)		$ 199
Approved Return on Equity, Percentage		7.85%
Commonwealth Edison Co [Member] | Illinois 2022 Electric Distribution Base Rate Case | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Approved Return on Equity, Percentage		7.78%
Public Utilities Requested Rate Increase (Decrease), Prior Year Annual Reconciliation		$ 55
Public Utilities, Approved Equity Capital Structure, Percentage		5.91%
Basis points for ComEd's Revenue Requirement		580
Commonwealth Edison Co [Member] | Illinois 2022 Electric Distribution Base Rate Case | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)		$ 144
Approved Return on Equity, Percentage		7.85%
Public Utilities, Approved Equity Capital Structure, Percentage		5.94%
Basis points for ComEd's Revenue Requirement		580
Commonwealth Edison Co [Member] | Illinois 2022 Electric Distribution Base Rate Case | Performance Metrics Penalty | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Basis points for ComEd's Revenue Requirement		7
PECO Energy Co [Member] | Pennsylvania 2022 Natural Gas Distribution Base Rate Case
Regulatory Matters Completed Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)						$ 82
Approved Revenue Requirement Increase (Decrease)			$ 55
Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount													$ 203
Approved Revenue Requirement Increase (Decrease)												$ 140
Approved Return on Equity, Percentage												9.50%
Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												$ 59
Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												39
Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												42
Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | Offsets | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage									25.00%
Baltimore Gas and Electric Company [Member] | Maryland 2020 Natural Gas Distribution Base Rate Case [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount													$ 108
Approved Revenue Requirement Increase (Decrease)												$ 74
Approved Return on Equity, Percentage												9.65%
Baltimore Gas and Electric Company [Member] | Maryland 2020 Natural Gas Distribution Base Rate Case [Member] | 2021
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												$ 53
Baltimore Gas and Electric Company [Member] | Maryland 2020 Natural Gas Distribution Base Rate Case [Member] | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												11
Baltimore Gas and Electric Company [Member] | Maryland 2020 Natural Gas Distribution Base Rate Case [Member] | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)												$ 10
Baltimore Gas and Electric Company [Member] | Maryland 2020 Natural Gas Distribution Base Rate Case [Member] | Offsets | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage									50.00%
Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member]
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount											$ 104
Approved Revenue Requirement Increase (Decrease)										$ 52
Approved Return on Equity, Percentage										9.55%
Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)										$ 21
Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2023
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)										16
Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2024
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)										$ 15
Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | Offsets | 2022
Regulatory Matters Completed Rate Cases [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Percentage							25.00%
Delmarva Power and Light Company [Member] | 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 [Member] | 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 [Member] | 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 [Member] | Maryland 2022 Electric Distribution Base Rate Case | 2025
Regulatory Matters Completed Rate Cases [Line Items]
Approved Revenue Requirement Increase (Decrease)	$ 6