Debt and Credit Agreements - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Jan. 10, 2023	Oct. 07, 2022
Corporate, Non-Segment [Member] | ShortTermDebt03232017
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 500
Corporate, Non-Segment [Member] | ShortTermDebt03232017 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	SOFR plus 0.90
Corporate, Non-Segment [Member] | ShortTermDebt03142023
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 300
Corporate, Non-Segment [Member] | ShortTermDebt03242023
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	200
Commonwealth Edison Co [Member] | ShortTermDebtSOFRplus075Oct2023
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 150
Commonwealth Edison Co [Member] | ShortTermDebtSOFRplus075Oct2023 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	SOFR plus 0.75
Commonwealth Edison Co [Member] | FMB490Feb2033 | First Mortgage [Member]
Short-term Debt [Line Items]
Debt Instrument, Face Amount		$ 400
Commonwealth Edison Co [Member] | FMB530Feb2053 | First Mortgage [Member]
Short-term Debt [Line Items]
Debt Instrument, Face Amount		$ 575
Commonwealth Edison Co [Member] | ShortTermDebtSOFRplus100May72024
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 400
Commonwealth Edison Co [Member] | ShortTermDebtSOFRplus100May72024 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	SOFR plus 1.00%
Revolving Credit Facility [Member] | Corporate, Non-Segment [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	$ 0
Line of Credit Facility, Maximum Borrowing Capacity	900
Revolving Credit Facility [Member] | Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	1,000
Revolving Credit Facility [Member] | PECO Energy Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	600
Revolving Credit Facility [Member] | Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	600
Revolving Credit Facility [Member] | Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	300
Revolving Credit Facility [Member] | Delmarva Power and Light Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	300
Revolving Credit Facility [Member] | Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Amount Outstanding During Period	0
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Letter of Credit | Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 40
Letter of Credit | PECO Energy Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			40
Letter of Credit | Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			15
Letter of Credit | Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			15
Letter of Credit | Delmarva Power and Light Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			15
Letter of Credit | Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity			$ 15