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Significant Accounting Policies Revenue Initial Application Period Cumulative Effect Transition (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 31, 2018 | Sep. 30, 2018 | Jun. 30, 2018 | Mar. 31, 2018 | Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Mar. 23, 2016 | Dec. 31, 2016 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  | $ 19,168 | $ 17,394 | $ 16,330
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  | (16,879) | (15,964) | (14,988)
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues | $ 8,814 | $ 9,403 | $ 8,076 | $ 9,693 | $ 8,384 | $ 8,768 | $ 7,665 | $ 8,747 |  |  | 35,985 | 33,565 | 31,366
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | (62) | 207 | 48
Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 17,360 | 16,324
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | (16,171) | (15,036)
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 33,531 | 31,360
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 34 | 6
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 207 | 48
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 34 | 6
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 207 | 48
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Exelon Generation Co L L C [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  | 19,169 | 17,385 | 16,318
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 1,268 | 1,115 | 1,439
Revenues | 5,069 | 5,278 | 4,579 | 5,512 | 4,657 | 4,750 | 4,216 | 4,878 |  |  | 20,437 | 18,500 | 17,757
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Exelon Generation Co L L C [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Exelon Generation Co L L C [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 17,351 | 16,312
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 1,115 | 1,439
Revenues |  |  |  |  |  |  |  |  |  |  |  | 18,466 | 17,751
Exelon Generation Co L L C [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Exelon Generation Co L L C [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 34 | 6
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 34 | 6
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Exelon Generation Co L L C [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Commonwealth Edison Co [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 5,884 | 5,478 | 5,263
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 27 | 15 | 15
Revenues | 1,373 | 1,598 | 1,398 | 1,512 | 1,309 | 1,571 | 1,357 | 1,298 |  |  | 5,882 | 5,536 | 5,254
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | (29) | 43 | (24)
Commonwealth Edison Co [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 5,521 | 5,239
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 15 | 15
Revenues |  |  |  |  |  |  |  |  |  |  |  | 5,536 | 5,254
Commonwealth Edison Co [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | (43) | 24
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 43 | (24)
PECO Energy Co [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 2,469 | 2,369 | 2,524
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  | 568 | 494 | 462
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 8 | 7 | 8
Revenues | 765 | 757 | 653 | 866 | 729 | 715 | 630 | 796 |  |  | 3,038 | 2,870 | 2,994
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | (7) | 0 | 0
PECO Energy Co [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 2,369 | 2,524
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 494 | 462
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 7 | 8
Revenues |  |  |  |  |  |  |  |  |  |  |  | 2,870 | 2,994
PECO Energy Co [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Baltimore Gas and Electric Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 2,428 | 2,384 | 2,531
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  | 738 | 652 | 628
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 29 | 16 | 21
Revenues | 799 | 731 | 662 | 977 | 813 | 738 | 674 | 951 |  |  | 3,169 | 3,176 | 3,233
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | (26) | 124 | 53
Baltimore Gas and Electric Company [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 2,484 | 2,603
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 676 | 609
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 16 | 21
Revenues |  |  |  |  |  |  |  |  |  |  |  | 3,176 | 3,233
Baltimore Gas and Electric Company [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | (100) | (72)
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | (24) | 19
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  |  | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 124 | 53
Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 4,609 | 4,428 |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  | 181 | 161 |
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 15 | 50 |
Revenues | 1,117 | 1,361 | 1,076 | 1,251 | 1,121 | 1,310 | 1,074 | 1,175 |  |  | 4,805 | 4,679 |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | 0 | 40 |
Potomac Electric Power Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 2,233 | 2,126 | 2,167
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 6 | 6 | 5
Revenues | 531 | 628 | 523 | 557 | 510 | 604 | 514 | 530 |  |  | 2,239 | 2,158 | 2,186
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | 0 | 26 | 14
Potomac Electric Power Company [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 2,152 | 2,181
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 6 | 5
Revenues |  |  |  |  |  |  |  |  |  |  |  | 2,158 | 2,186
Potomac Electric Power Company [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | (26) | (14)
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 26 | 14
Delmarva Power & Light Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 1,139 | 1,125 | 1,128
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  | 181 | 161 | 148
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 8 | 8 | 7
Revenues | 331 | 328 | 289 | 384 | 330 | 327 | 282 | 362 |  |  | 1,332 | 1,300 | 1,277
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | 4 | 6 | (6)
Delmarva Power & Light Company [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 1,131 | 1,122
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 161 | 148
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 8 | 7
Revenues |  |  |  |  |  |  |  |  |  |  |  | 1,300 | 1,277
Delmarva Power & Light Company [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | (6) | 6
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 6 | (6)
Atlantic City Electric Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  | 1,237 | 1,176 | 1,245
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  | 3 | 2 | 3
Revenues | $ 254 | $ 406 | $ 265 | $ 310 | $ 271 | $ 370 | $ 270 | $ 275 |  |  | 1,236 | 1,186 | 1,257
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  | (4) | 8 | 9
Atlantic City Electric Company [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | 1,184 | 1,254
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 2 | 3
Revenues |  |  |  |  |  |  |  |  |  |  |  | 1,186 | 1,257
Atlantic City Electric Company [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Electric Revenue |  |  |  |  |  |  |  |  |  |  |  | (8) | (9)
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenues |  |  |  |  |  |  |  |  |  |  |  | 0 | 0
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  |  |  | 8 | $ 9
Successor [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  | $ 0 |  | 0 |
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Electric Revenue |  |  |  |  |  |  |  |  |  | 3,463 |  | 4,428 |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  | 92 |  | 161 |
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  | 45 | $ 15 | 50 |
Revenues |  |  |  |  |  |  |  |  |  | 3,643 |  | 4,679 |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  | 43 |  | 40 |
Successor [Member] | Pepco Holdings LLC [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Electric Revenue |  |  |  |  |  |  |  |  |  | 3,506 |  | 4,468 |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  | 92 |  | 161 |
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  | 45 |  | 50 |
Revenues |  |  |  |  |  |  |  |  |  | 3,643 |  | 4,679 |
Successor [Member] | Pepco Holdings LLC [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Regulated Operating Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Electric Revenue |  |  |  |  |  |  |  |  |  | (43) |  | (40) |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Operating revenues from affiliates |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Revenues |  |  |  |  |  |  |  |  |  | 0 |  | 0 |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  |  | $ 43 |  | $ 40 |
Predecessor [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  | $ 0 |  |  |  |
Regulated Operating Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Electric Revenue |  |  |  |  |  |  |  |  | 1,122 |  |  |  |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  | 57 |  |  |  |
Operating revenues from affiliates |  |  |  |  |  |  |  |  | 0 |  |  |  |
Revenues |  |  |  |  |  |  |  |  | 1,153 |  |  |  |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  | (26) |  |  |  |
Predecessor [Member] | Pepco Holdings LLC [Member] | Calculated under Revenue Guidance in Effect before Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Regulated Operating Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Electric Revenue |  |  |  |  |  |  |  |  | 1,096 |  |  |  |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  | 57 |  |  |  |
Operating revenues from affiliates |  |  |  |  |  |  |  |  | 0 |  |  |  |
Revenues |  |  |  |  |  |  |  |  | 1,153 |  |  |  |
Predecessor [Member] | Pepco Holdings LLC [Member] | Difference between Revenue Guidance in Effect before and after Topic 606 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Revenue, Initial Application Period Cumulative Effect Transition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Electrical Generation Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Regulated Operating Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Electric Revenue |  |  |  |  |  |  |  |  | 26 |  |  |  |
Gas Domestic Regulated Revenue |  |  |  |  |  |  |  |  | 0 |  |  |  |
Operating revenues from affiliates |  |  |  |  |  |  |  |  | 0 |  |  |  |
Revenues |  |  |  |  |  |  |  |  | 0 |  |  |  |
Revenue from Contract with Customer, Including Assessed Tax |  |  |  |  |  |  |  |  | $ (26) |  |  |  |

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