Related Party Transactions - Current Receivables From/Payables To Affiliates (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Related Party
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	$ 281	$ 251
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	4	3
Commonwealth Edison Co | Affiliated Entities
Related Party Transaction [Line Items]
Accounts payable	77	72
Commonwealth Edison Co | Related Party
Related Party Transaction [Line Items]
Accounts payable	77	72
Receivable from affiliates	4	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	0	1
PECO Energy Co | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
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
Related Party Transaction [Line Items]
Accounts payable	41	39
PECO Energy Co | Related Party
Related Party Transaction [Line Items]
Accounts payable	41	39
Receivable from affiliates	0	2
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
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
Related Party Transaction [Line Items]
Accounts payable	48	35
Baltimore Gas and Electric Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	48	35
Receivable from affiliates	0	0
Pepco Holdings LLC | Affiliated Entities
Related Party Transaction [Line Items]
Accounts payable	18	15
Pepco Holdings LLC | Related Party
Related Party Transaction [Line Items]
Accounts payable	66	59
Receivable from affiliates	8	3
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	0	1
Potomac Electric Power Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Potomac Electric Power Company | Affiliated Entities
Related Party Transaction [Line Items]
Accounts payable	37	32
Potomac Electric Power Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	37	32
Receivable from affiliates	1	2
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	0	1
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
Related Party Transaction [Line Items]
Accounts payable	26	25
Delmarva Power & Light Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	26	25
Receivable from affiliates	0	1
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	7	3
Atlantic City Electric Company | Affiliated Entities
Related Party Transaction [Line Items]
Accounts payable	22	25
Atlantic City Electric Company | Related Party
Related Party Transaction [Line Items]
Accounts payable	22	25
Receivable from affiliates	7	3
Software License | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	67	64
Software License | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	37	36
Software License | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	47	33
Software License | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	7	5
Software License | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	21	17
Software License | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	14	12
Software License | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	11
Software License | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
Software License | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	204	179
PHI Service Company | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company | 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 | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
PHI Service Company | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	15	14
PHI Service Company | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	11
PHI Service Company | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	10	11
PHI Service Company | Other Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	37	36
Other Legal Entities | Commonwealth Edison Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	10	8
Other Legal Entities | PECO Energy Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	4	3
Other Legal Entities | Baltimore Gas And Electric Company Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	2
Other Legal Entities | Pepco Holdings LLC Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	10	10
Other Legal Entities | Potomac Electric Power Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Other Legal Entities | Delmarva Power and Light Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Other Legal Entities | Atlantic City Electric Co Affiliate
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Other Legal Entities | Affiliated Entities
Related Party Transaction [Line Items]
Accounts payable	12	8
Other Legal Entities | Related Party
Related Party Transaction [Line Items]
Receivable from affiliates	$ 28	$ 25