v3.26.3
Fair Value Measures and Disclosures - Narrative (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Mark-to-market derivative liabilities (current liabilities) $ 21 $ 30
Mark-to-market derivative liabilities (noncurrent liabilities) 96 106
Commonwealth Edison Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Mark-to-market derivative liabilities (current liabilities) 21 25
Mark-to-market derivative liabilities (noncurrent liabilities) 96 106
Fair Value, Recurring [Member]    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 1,718 825
Fair Value, Recurring [Member] | Commonwealth Edison Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 573 393
Mark-to-market derivative liabilities (current liabilities) 21 25
Mark-to-market derivative liabilities (noncurrent liabilities) 96 106
Fair Value, Recurring [Member] | PECO Energy Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 81 93
Fair Value, Recurring [Member] | Baltimore Gas and Electric Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 834 205
Fair Value, Recurring [Member] | Pepco Holdings LLC    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 205 83
Fair Value, Recurring [Member] | Potomac Electric Power Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 102 33
Fair Value, Recurring [Member] | Delmarva Power and Light Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 74 3
Fair Value, Recurring [Member] | Atlantic City Electric Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 0 0
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 166 180
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue | Commonwealth Edison Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 75 77
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue | PECO Energy Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 26 23
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue | Baltimore Gas and Electric Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 11 15
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue | Pepco Holdings LLC    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 43 56
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:CashAndCashEquivalentsAtCarryingValue | Atlantic City Electric Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 14 22
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:OtherAssetsNoncurrent    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 49 50
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:OtherAssetsNoncurrent | Commonwealth Edison Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 49 50
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 236 196
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue | Commonwealth Edison Co    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 231 193
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue | Pepco Holdings LLC    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 5 2
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue | Potomac Electric Power Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 16 22
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue | Delmarva Power and Light Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure 7 9
Fair Value, Recurring [Member] | Balance Sheet Location [Axis]: us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue | Atlantic City Electric Company    
Fair Value Assets Liabilities Measured On Recurring Basis [Line Items]    
Cash and Cash Equivalents, Fair Value Disclosure $ 5 $ 2