Accounts Receivable - Unbilled Customer Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	$ 991	$ 912
Commonwealth Edison Co
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	351	223
PECO Energy Co
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	185	219
Baltimore Gas and Electric Company
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	208	247
Pepco Holdings LLC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	247	223
Potomac Electric Power Company
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	109	103
Delmarva Power & Light Company
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	64	74
Atlantic City Electric Company
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	$ 74	$ 46