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Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Debt and Credit Agreements - Schedule of Outstanding Long-term Debt (Details) - USD ($) $ in Millions			12 Months Ended
	Oct. 07, 2022	Jan. 21, 2022	Dec. 31, 2022	Dec. 31, 2023	Jan. 24, 2022
Debt Instrument [Line Items]
Long-term debt, gross			$ 36,779	$ 40,889
Unamortized debt discount and premium, net			74	80
Unamortized debt issuance costs			(257)	(296)
Long-term debt (including amounts due within one year)			626	582
Long-term debt, current maturities			(1,802)	(1,403)
Exelon Generation Co L L C
Debt Instrument [Line Items]
Proceeds from sale and collection of notes receivable			258
Senior unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			8,324	10,824
Loan agreements
Debt Instrument [Line Items]
Long-term debt, gross			1,400	$ 500
Minimum \| Senior unsecured notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.75%
Long-term debt, maturity date				Jun. 15, 2025
Maximum \| Senior unsecured notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term debt, maturity date				Mar. 15, 2053
Maximum \| Loan agreements
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.23%
Long-term debt, maturity date				Apr. 08, 2024
Corporate, Non-Segment
Debt Instrument [Line Items]
Long-term debt, gross			9,489	$ 11,139
Unamortized debt discount and premium, net			(10)	(13)
Unamortized debt issuance costs			(51)	(65)
Long-term debt (including amounts due within one year)			164	152
Long-term debt, current maturities			(850)	(500)
Long-term debt			8,742	10,713
Corporate, Non-Segment \| Senior unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			8,139	10,639
Corporate, Non-Segment \| Loan agreements
Debt Instrument [Line Items]
Long-term debt, gross		$ 300	$ 1,350	$ 500
Corporate, Non-Segment \| Loan agreements \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated borrowing, interest rate	0.85%	0.65%
Corporate, Non-Segment \| Loans Payable Three
Debt Instrument [Line Items]
Long-term debt, gross					$ 250
Corporate, Non-Segment \| Loans Payable Two \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated borrowing, interest rate		0.65%
Corporate, Non-Segment \| Minimum \| Senior unsecured notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.75%
Long-term debt, maturity date				Jun. 15, 2025
Corporate, Non-Segment \| Maximum \| Senior unsecured notes
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term debt, maturity date				Mar. 15, 2053
Corporate, Non-Segment \| Maximum \| Loan agreements
Debt Instrument [Line Items]
Long-term debt, maturity date				Apr. 08, 2024