Debt and Credit Agreements - Summary of Outstanding Long-term Debt (Details) - USD ($) $ in Millions	Oct. 07, 2022	Jan. 21, 2022	Dec. 31, 2023	Dec. 31, 2022
Debt Instrument [Line Items]
Long-term debt, gross			$ 40,889	$ 36,779
Unamortized debt discount and premium, net			(80)	(74)
Unamortized debt issuance costs			(296)	(257)
Fair value adjustment			582	626
Long-term debt, current maturities			(1,403)	(1,802)
Corporate, Non-Segment
Debt Instrument [Line Items]
Long-term debt, gross			11,139	9,489
Unamortized debt discount and premium, net			13	10
Unamortized debt issuance costs			(65)	(51)
Fair value adjustment			152	164
Long-term debt, current maturities			(500)	(850)
Long-term debt			10,713	8,742
First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 24,776	22,651
First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			1.05%
Long-term debt, maturity date			Mar. 15, 2024
First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.90%
Long-term debt, maturity date			Nov. 08, 2053
Senior unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			$ 10,824	8,324
Senior unsecured notes | Corporate, Non-Segment
Debt Instrument [Line Items]
Long-term debt, gross			$ 10,639	8,139
Senior unsecured notes | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.75%
Long-term debt, maturity date			Jun. 15, 2025
Senior unsecured notes | Minimum | Corporate, Non-Segment
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.75%
Long-term debt, maturity date			Jun. 15, 2025
Senior unsecured notes | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.60%
Long-term debt, maturity date			Mar. 15, 2053
Senior unsecured notes | Maximum | Corporate, Non-Segment
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.60%
Long-term debt, maturity date			Mar. 15, 2053
Unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			$ 4,650	4,250
Unsecured notes | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.25%
Long-term debt, maturity date			Aug. 15, 2026
Unsecured notes | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.35%
Long-term debt, maturity date			Jun. 01, 2053
Notes payable and other
Debt Instrument [Line Items]
Long-term debt, gross			$ 84	86
Notes payable and other | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			1.64%
Long-term debt, maturity date			Jan. 10, 2025
Notes payable and other | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.49%
Long-term debt, maturity date			May 01, 2053
Long-term software licensing agreement
Debt Instrument [Line Items]
Long-term debt, gross			$ 12	25
Long-term software licensing agreement | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.30%
Long-term debt, maturity date			May 01, 2024
Long-term software licensing agreement | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.95%
Long-term debt, maturity date			Dec. 01, 2025
Unsecured tax-exempt bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 33	33
Unsecured tax-exempt bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.15%
Unsecured tax-exempt bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.20%
Long-term debt, maturity date			Jul. 01, 2024
Medium-terms notes (unsecured)
Debt Instrument [Line Items]
Long-term debt, gross			$ 10	10
Medium-terms notes (unsecured) | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.72%
Long-term debt, maturity date			Feb. 01, 2027
Loan agreements
Debt Instrument [Line Items]
Long-term debt, gross			$ 500	1,400
Loan agreements | Corporate, Non-Segment
Debt Instrument [Line Items]
Long-term debt, gross		$ 300	$ 500	1,350
Loan agreements | Corporate, Non-Segment | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated borrowing, interest rate	0.85%	0.65%
Loan agreements | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.23%
Long-term debt, maturity date			Apr. 08, 2024
Loan agreements | Maximum | Corporate, Non-Segment
Debt Instrument [Line Items]
Long-term debt, maturity date			Apr. 08, 2024
ComEd Financing III Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt				206
ComEd Financing III Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.35%
Long-term debt, maturity date			Mar. 15, 2033
PECO Trust III Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 81	81
PECO Trust III Affiliate | Long-term debt to financing trusts | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.38%
PECO Trust III Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			10.50%
Long-term debt, maturity date			Apr. 06, 2028
PECO Trust IV Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 103	103
PECO Trust IV Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			5.75%
Long-term debt, maturity date			Jun. 15, 2033
Related Party | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 390	390
Nonrelated Party
Debt Instrument [Line Items]
Long-term debt			39,692	35,272
Commonwealth Edison Co
Debt Instrument [Line Items]
Long-term debt, gross			11,611	10,637
Unamortized debt discount and premium, net			(28)	(27)
Unamortized debt issuance costs			(97)	(92)
Long-term debt, current maturities			(250)	0
Long-term debt			11,236	10,518
Commonwealth Edison Co | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 11,603	10,629
Commonwealth Edison Co | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.20%
Long-term debt, maturity date			Nov. 01, 2024
Commonwealth Edison Co | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.45%
Long-term debt, maturity date			Feb. 01, 2053
Commonwealth Edison Co | Notes payable and other
Debt Instrument [Line Items]
Total finance lease liabilities			$ 8	8
Commonwealth Edison Co | Notes payable and other | Maximum
Debt Instrument [Line Items]
Long-term debt, maturity date			May 01, 2053
Lessee, finance lease, discount rate			7.49%
Commonwealth Edison Co | ComEd Financing III Affiliate
Debt Instrument [Line Items]
Unamortized debt issuance costs			$ (1)	(1)
Commonwealth Edison Co | ComEd Financing III Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 206	206
Commonwealth Edison Co | ComEd Financing III Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.35%
Commonwealth Edison Co | Related Party
Debt Instrument [Line Items]
Long-term debt			$ 205	205
Commonwealth Edison Co | Related Party | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			206	206
Commonwealth Edison Co | Nonrelated Party
Debt Instrument [Line Items]
Long-term debt			11,236	10,518
PECO Energy Co
Debt Instrument [Line Items]
Long-term debt, gross			5,200	4,675
Unamortized debt discount and premium, net			(24)	(24)
Unamortized debt issuance costs			(42)	(39)
Long-term debt, current maturities			0	(50)
Long-term debt			5,134	4,562
PECO Energy Co | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 5,200	4,625
PECO Energy Co | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.80%
Long-term debt, maturity date			Oct. 15, 2025
PECO Energy Co | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			5.95%
Long-term debt, maturity date			Aug. 15, 2052
PECO Energy Co | Loan agreements
Debt Instrument [Line Items]
Long-term debt, gross			$ 0	$ 50
PECO Energy Co | Loan agreements | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.00%
Long-term debt, maturity date			Jun. 20, 2023
PECO Energy Co | PECO Trust III Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 81	$ 81
PECO Energy Co | PECO Trust III Affiliate | Long-term debt to financing trusts | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.38%
PECO Energy Co | PECO Trust III Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			10.50%
Long-term debt, maturity date			Apr. 06, 2028
PECO Energy Co | PECO Trust IV Affiliate | Long-term debt to financing trusts
Debt Instrument [Line Items]
Long-term debt			$ 103	103
PECO Energy Co | PECO Trust IV Affiliate | Long-term debt to financing trusts | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			5.75%
Long-term debt, maturity date			Jun. 15, 2033
PECO Energy Co | Related Party
Debt Instrument [Line Items]
Long-term debt			$ 184	184
PECO Energy Co | Nonrelated Party
Debt Instrument [Line Items]
Long-term debt			5,134	4,562
Baltimore Gas and Electric Company
Debt Instrument [Line Items]
Long-term debt, gross			4,650	4,250
Unamortized debt discount and premium, net			(12)	(13)
Unamortized debt issuance costs			(36)	(30)
Long-term debt, current maturities			0	(300)
Long-term debt			4,602	3,907
Baltimore Gas and Electric Company | Unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			$ 4,650	4,250
Baltimore Gas and Electric Company | Unsecured notes | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.25%
Long-term debt, maturity date			Aug. 15, 2026
Baltimore Gas and Electric Company | Unsecured notes | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			6.35%
Long-term debt, maturity date			Jun. 01, 2053
Pepco Holdings LLC
Debt Instrument [Line Items]
Long-term debt, gross			$ 8,274	7,701
Total finance lease liabilities			74	76
Unamortized debt discount and premium, net			0	4
Unamortized debt issuance costs			(55)	(47)
Fair value adjustment			429	462
Long-term debt due within one year			(644)	(591)
Long-term debt			8,004	7,529
Pepco Holdings LLC | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 7,972	7,397
Pepco Holdings LLC | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			1.05%
Long-term debt, maturity date			Mar. 15, 2024
Pepco Holdings LLC | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.90%
Long-term debt, maturity date			Nov. 08, 2053
Pepco Holdings LLC | Senior unsecured notes
Debt Instrument [Line Items]
Long-term debt, gross			$ 185	185
Pepco Holdings LLC | Senior unsecured notes | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.45%
Long-term debt, maturity date			Aug. 15, 2032
Pepco Holdings LLC | Finance Leases
Debt Instrument [Line Items]
Total finance lease liabilities			$ 74	76
Pepco Holdings LLC | Finance Leases | Minimum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jan. 10, 2025
Pepco Holdings LLC | Finance Leases | Maximum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jul. 10, 2031
Lessee, finance lease, discount rate			5.62%
Pepco Holdings LLC | Unsecured tax-exempt bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 33	33
Pepco Holdings LLC | Unsecured tax-exempt bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.15%
Pepco Holdings LLC | Unsecured tax-exempt bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.20%
Long-term debt, maturity date			Jul. 01, 2024
Pepco Holdings LLC | Medium-terms notes (unsecured)
Debt Instrument [Line Items]
Long-term debt, gross			$ 10	10
Pepco Holdings LLC | Medium-terms notes (unsecured) | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.72%
Long-term debt, maturity date			Feb. 01, 2027
Potomac Electric Power Company
Debt Instrument [Line Items]
Long-term debt, gross			$ 4,151	3,800
Total finance lease liabilities			26	25
Unamortized debt discount and premium, net			2	2
Unamortized debt issuance costs			(57)	(51)
Long-term debt due within one year			(405)	(4)
Long-term debt			3,691	3,747
Potomac Electric Power Company | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 4,125	3,775
Potomac Electric Power Company | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.32%
Long-term debt, maturity date			Mar. 15, 2024
Potomac Electric Power Company | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.90%
Long-term debt, maturity date			Mar. 15, 2053
Potomac Electric Power Company | Finance Leases
Debt Instrument [Line Items]
Total finance lease liabilities			$ 26	25
Potomac Electric Power Company | Finance Leases | Minimum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jan. 10, 2025
Potomac Electric Power Company | Finance Leases | Maximum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jun. 10, 2031
Lessee, finance lease, discount rate			5.62%
Delmarva Power & Light Company
Debt Instrument [Line Items]
Long-term debt, gross			$ 2,096	1,949
Total finance lease liabilities			29	32
Unamortized debt discount and premium, net			0	0
Unamortized debt issuance costs			(16)	(11)
Long-term debt, current maturities			(79)	(79)
Long-term debt due within one year			(84)	(584)
Long-term debt			1,996	1,354
Delmarva Power & Light Company | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 2,024	1,874
Delmarva Power & Light Company | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			1.05%
Long-term debt, maturity date			Oct. 01, 2028
Delmarva Power & Light Company | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			5.72%
Long-term debt, maturity date			Nov. 08, 2053
Delmarva Power & Light Company | Finance Leases
Debt Instrument [Line Items]
Total finance lease liabilities			$ 29	32
Delmarva Power & Light Company | Finance Leases | Minimum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jan. 10, 2025
Delmarva Power & Light Company | Finance Leases | Maximum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jul. 10, 2031
Lessee, finance lease, discount rate			5.62%
Delmarva Power & Light Company | Unsecured tax-exempt bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 33	33
Delmarva Power & Light Company | Unsecured tax-exempt bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.15%
Delmarva Power & Light Company | Unsecured tax-exempt bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			4.20%
Long-term debt, maturity date			Jul. 01, 2024
Delmarva Power & Light Company | Medium-terms notes (unsecured)
Debt Instrument [Line Items]
Long-term debt, gross			$ 10	10
Delmarva Power & Light Company | Medium-terms notes (unsecured) | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			7.72%
Long-term debt, maturity date			Feb. 01, 2027
Atlantic City Electric Company
Debt Instrument [Line Items]
Long-term debt, gross			$ 1,842	1,767
Total finance lease liabilities			19	19
Unamortized debt discount and premium, net			0	(1)
Unamortized debt issuance costs			(9)	(9)
Long-term debt due within one year			(154)	(3)
Long-term debt			1,679	1,754
Atlantic City Electric Company | First Mortgage Bonds
Debt Instrument [Line Items]
Long-term debt, gross			$ 1,823	1,748
Atlantic City Electric Company | First Mortgage Bonds | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.25%
Long-term debt, maturity date			Sep. 01, 2024
Atlantic City Electric Company | First Mortgage Bonds | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			5.80%
Long-term debt, maturity date			Mar. 15, 2053
Atlantic City Electric Company | Finance Leases
Debt Instrument [Line Items]
Total finance lease liabilities			$ 19	$ 19
Atlantic City Electric Company | Finance Leases | Minimum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jan. 10, 2025
Atlantic City Electric Company | Finance Leases | Maximum
Debt Instrument [Line Items]
Long-term debt, maturity date			Jul. 10, 2031
Lessee, finance lease, discount rate			5.62%