Related Party Transactions - Current Receivables From/Payables To Affiliates (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Related Party
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	$ 251	$ 255
Accounts payable	5	5
Commonwealth Edison Co | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	3
Commonwealth Edison Co | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	72	74
Commonwealth Edison Co | Related Party
Related Party Transaction [Line Items]
Accounts payable	72	74
Receivable from affiliates	3	3
PECO Energy Co | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	2
PECO Energy Co | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	2
PECO Energy Co | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	39	42
PECO Energy Co | Related Party
Related Party Transaction [Line Items]
Accounts payable	39	42
Receivable from affiliates	2	4
Baltimore Gas and Electric Company | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	35	39
Baltimore Gas and Electric Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	35	39
Receivable from affiliates	0	0
Pepco Holdings LLC | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	15	14
Pepco Holdings LLC | Related Party
Related Party Transaction [Line Items]
Accounts payable	59	66
Receivable from affiliates	3	2
Potomac Electric Power Company | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Potomac Electric Power Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Potomac Electric Power Company | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	32	34
Potomac Electric Power Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	32	34
Receivable from affiliates	2	0
Delmarva Power & Light Company | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Delmarva Power & Light Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Company | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	25	22
Delmarva Power & Light Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	25	22
Receivable from affiliates	1	0
Atlantic City Electric Company | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	1
Atlantic City Electric Company | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	25	26
Atlantic City Electric Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	25	26
Receivable from affiliates	3	1
Software License | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	64	66
Software License | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	36	39
Software License | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	33	38
Software License | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	5	4
Software License | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	17	20
Software License | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	12	12
Software License | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	14
Software License | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Software License | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	179	193
PHI Service Company [Member] | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	14	13
PHI Service Company [Member] | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	8
PHI Service Company [Member] | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	9
PHI Service Company [Member] | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	36	30
Other Legal Entities [Member] | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	8	8
Other Legal Entities [Member] | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	3
Other Legal Entities [Member] | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	2	1
Other Legal Entities [Member] | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	10	10
Other Legal Entities [Member] | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Other Legal Entities [Member] | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Other Legal Entities [Member] | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
Other Legal Entities [Member] | Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts payable	8	4
Other Legal Entities [Member] | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	$ 25	$ 24