v3.26.1
Supplemental Financial Information - Cash Flow (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     $ 1,605 $ 1,506
Amortization of regulatory assets     315 296
Amortization of intangible assets, net     0 3
Accretion expense     1 1
Depreciation, amortization, and accretion     1,921 1,806
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     129 136
Allowance for credit losses     171 137
True-up adjustments to decoupling mechanisms and formula rates $ (70) $ (275) (102) (402)
Amortization of operating ROU asset     11 16
AFUDC - Equity (63) (43) (120) (81)
Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     98 397
Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (120) (81)
Commonwealth Edison Co        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     639 608
Amortization of regulatory assets     181 159
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     820 767
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     54 42
Allowance for credit losses     35 23
True-up adjustments to decoupling mechanisms and formula rates (55) (234) (46) (319)
Amortization of operating ROU asset     0 0
AFUDC - Equity (24) (14) (45) (26)
Commonwealth Edison Co | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     46 319
Commonwealth Edison Co | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (45) (26)
PECO Energy Co        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     246 219
Amortization of regulatory assets     1 2
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     247 221
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     8 3
Allowance for credit losses     48 50
True-up adjustments to decoupling mechanisms and formula rates 5 1 10 (8)
Amortization of operating ROU asset     0 0
AFUDC - Equity (11) (10) (21) (17)
PECO Energy Co | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     (10) 8
PECO Energy Co | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (21) (17)
Baltimore Gas and Electric Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     267 249
Amortization of regulatory assets     67 69
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     334 318
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     14 30
Allowance for credit losses     53 17
True-up adjustments to decoupling mechanisms and formula rates 5 (13) (18) (43)
Amortization of operating ROU asset     3 4
AFUDC - Equity (16) (9) (30) (18)
Baltimore Gas and Electric Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     18 43
Baltimore Gas and Electric Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (30) (18)
Pepco Holdings LLC        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     427 402
Amortization of regulatory assets     64 65
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     491 467
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     41 49
Allowance for credit losses     35 47
True-up adjustments to decoupling mechanisms and formula rates (24) (29) (48) (32)
Amortization of operating ROU asset     5 9
AFUDC - Equity (12) (10) (24) (20)
Pepco Holdings LLC | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     44 27
Pepco Holdings LLC | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (24) (20)
Potomac Electric Power Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     189 177
Amortization of regulatory assets     39 35
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     228 212
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     14 18
Allowance for credit losses     17 19
True-up adjustments to decoupling mechanisms and formula rates (15) (16) (14) (14)
Amortization of operating ROU asset     1 2
AFUDC - Equity (9) (8) (19) (15)
Potomac Electric Power Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     14 14
Potomac Electric Power Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (19) (15)
Delmarva Power and Light Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     120 113
Amortization of regulatory assets     13 13
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     133 126
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     7 8
Allowance for credit losses     7 11
True-up adjustments to decoupling mechanisms and formula rates 2 0 (5) (5)
Amortization of operating ROU asset     2 3
AFUDC - Equity (2) (1) (3) (3)
Delmarva Power and Light Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     5 5
Delmarva Power and Light Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (3) (3)
Atlantic City Electric Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     116 111
Amortization of regulatory assets     12 16
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation, amortization, and accretion     128 127
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     5 6
Allowance for credit losses     11 17
True-up adjustments to decoupling mechanisms and formula rates (11) (13) (29) (13)
Amortization of operating ROU asset     1 1
AFUDC - Equity $ (1) $ (1) (2) (2)
Atlantic City Electric Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     25 8
Atlantic City Electric Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     $ (2) $ (2)