v3.25.2
Supplemental Financial Information - Cash Flow (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     $ 1,506 $ 1,436
Amortization of regulatory assets     296 333
Amortization of intangible assets, net     3 4
Accretion expense     1 1
Depreciation and amortization     1,806 1,774
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     136 120
Allowance for credit losses     137 93
True-up adjustments to decoupling mechanisms and formula rates $ (275) $ (80) (402) 25
Amortization of operating ROU asset     16 19
AFUDC - Equity (43) (38) (81) (78)
Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     397 (15)
Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (81) (78)
Commonwealth Edison Co        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     608 573
Amortization of regulatory assets     159 164
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     767 737
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     42 36
Allowance for credit losses     23 8
True-up adjustments to decoupling mechanisms and formula rates (234) (43) (319) (24)
Amortization of operating ROU asset     0 0
AFUDC - Equity (14) (9) (26) (19)
Commonwealth Edison Co | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     319 24
Commonwealth Edison Co | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (26) (19)
PECO Energy Co        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     219 203
Amortization of regulatory assets     2 7
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     221 210
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     3 0
Allowance for credit losses     50 47
True-up adjustments to decoupling mechanisms and formula rates 1 0 (8) (2)
Amortization of operating ROU asset     0 0
AFUDC - Equity (10) (8) (17) (16)
PECO Energy Co | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     8 2
PECO Energy Co | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (17) (16)
Baltimore Gas and Electric Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     249 247
Amortization of regulatory assets     69 65
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     318 312
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     30 31
Allowance for credit losses     17 11
True-up adjustments to decoupling mechanisms and formula rates (13) (23) (43) 19
Amortization of operating ROU asset     4 3
AFUDC - Equity (9) (6) (18) (13)
Baltimore Gas and Electric Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     43 (19)
Baltimore Gas and Electric Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (18) (13)
Pepco Holdings LLC        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     402 383
Amortization of regulatory assets     65 97
Amortization of intangible assets, net     0 0
Accretion expense     0 1
Depreciation and amortization     467 481
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     49 46
Allowance for credit losses     47 27
True-up adjustments to decoupling mechanisms and formula rates (29) (14) (32) 32
Amortization of operating ROU asset     9 13
AFUDC - Equity (10) (15) (20) (30)
Pepco Holdings LLC | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     27 (22)
Pepco Holdings LLC | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (20) (30)
Potomac Electric Power Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     177 164
Amortization of regulatory assets     35 41
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     212 205
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     18 16
Allowance for credit losses     19 16
True-up adjustments to decoupling mechanisms and formula rates (16) 7 (14) 37
Amortization of operating ROU asset     2 3
AFUDC - Equity (8) (12) (15) (23)
Potomac Electric Power Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     14 (37)
Potomac Electric Power Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (15) (23)
Delmarva Power and Light Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     113 107
Amortization of regulatory assets     13 15
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     126 122
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     8 7
Allowance for credit losses     11 3
True-up adjustments to decoupling mechanisms and formula rates 0 0 (5) 4
Amortization of operating ROU asset     3 3
AFUDC - Equity (1) (3) (3) (6)
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 4
Delmarva Power and Light Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     (3) (6)
Atlantic City Electric Company        
Depreciation, Amortization and Accretion [Abstract]        
Property, plant and equipment     111 105
Amortization of regulatory assets     16 41
Amortization of intangible assets, net     0 0
Accretion expense     0 0
Depreciation and amortization     127 146
Other Non-Cash Operating Activities [Abstract]        
Pension and non-pension postretirement benefit costs     6 7
Allowance for credit losses     17 7
True-up adjustments to decoupling mechanisms and formula rates (13) (21) (13) (9)
Amortization of operating ROU asset     1 2
AFUDC - Equity $ (1) $ 0 (2) (1)
Atlantic City Electric Company | Other Non-Cash Activity        
Other Non-Cash Operating Activities [Abstract]        
True-up adjustments to decoupling mechanisms and formula rates     8 11
Atlantic City Electric Company | Return on borrowed funds        
Other Non-Cash Operating Activities [Abstract]        
AFUDC - Equity     $ (2) $ (1)