Debt and Credit Agreements - Narrative (Details) - USD ($) $ in Millions			9 Months Ended
	Oct. 07, 2022	Aug. 11, 2022	Sep. 30, 2022
Short-term Debt [Line Items]
Proceeds from (Repayments of) Debt		$ 575
Corporate, Non-Segment [Member]
Short-term Debt [Line Items]
Proceeds from (Repayments of) Debt		$ 575
Debt Instrument [Line Items]
Notes Receivable, Related Parties			$ 319
Proceeds from Sale and Collection of Notes Receivable			258
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 0.65
Corporate, Non-Segment [Member] | ShortTermDebt03312021.1
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable			$ 150
Corporate, Non-Segment [Member] | ShortTermDebt03312021.1 | London Interbank Offered Rate (LIBOR) [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms			LIBOR plus 0.65
Corporate, Non-Segment [Member] | ShortTermDebtSOFRplus0.75Jan2023
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable			$ 1,150
Corporate, Non-Segment [Member] | ShortTermDebtSOFRplus0.75Jan2023 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms			SOFR plus 0.75
Corporate, Non-Segment [Member] | ShortTermDebtSOFRplus075PLUS22.5BPincreaseJan2023 | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms			SOFR plus 0.975%
Subsequent Event [Member] | Corporate, Non-Segment [Member]
Short-term Debt [Line Items]
Proceeds from (Repayments of) Debt	$ 575
Letter of Credit | Subsequent Event [Member] | Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	40
Letter of Credit | Subsequent Event [Member] | PECO Energy Co [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	40
Letter of Credit | Subsequent Event [Member] | Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	15
Letter of Credit | Subsequent Event [Member] | Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	15
Letter of Credit | Subsequent Event [Member] | Delmarva Power and Light Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	15
Letter of Credit | Subsequent Event [Member] | Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 15
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