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Mergers, Acquisitions and Dispositions Mergers, Acquisitions and Dispositions - Narrative (Details) $ in Millions |  |  |  |  |  |  |  |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 09, 2018 USD ($) | Apr. 04, 2018 USD ($) | Feb. 28, 2018 USD ($) | Nov. 07, 2017 USD ($) | Mar. 31, 2017 USD ($) | Sep. 01, 2016 USD ($) | Jun. 16, 2016 USD ($) | Mar. 23, 2016 USD ($) | Dec. 31, 2018 USD ($) MW | Sep. 30, 2018 USD ($) | Jun. 30, 2018 USD ($) | Mar. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Mar. 23, 2016 USD ($) | Sep. 30, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2018 USD ($) MW | Dec. 31, 2017 USD ($) MW | Dec. 31, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 24, 2016 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets held for sale |  |  |  |  |  |  |  |  |  | $ 904 |  |  |  | $ 0 |  |  |  |  |  |  |  |  | $ 904 |  | $ 0 |  |  |  |  |
Liabilities held for sale |  |  |  |  |  |  |  |  |  | 777 |  |  |  | 0 |  |  |  |  |  |  |  |  | 777 |  | 0 |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20 |  |  |  | $ 2 |  |  |
Deconsolidation, Gain (Loss), Amount |  |  |  |  | $ 213 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 213 |  | 0 |  |  |
Business Combination, Contingent Consideration, Asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 235
Payments to Acquire Businesses, Gross |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 154 |  | 208 |  | 6,923 |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7 | [1] | 16 | [1] | 143 |  |  |
Line of credit facility, maximum borrowing capacity | [2] |  |  |  |  |  |  |  |  | 9,704 |  |  |  |  |  |  |  |  |  |  |  |  | 9,704 |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 127 |  |  |  |  |  |  |  |  |  |  |  |  | 127 |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 8,814 | $ 9,403 | $ 8,076 | $ 9,693 | 8,384 | $ 8,768 | $ 7,665 | $ 8,747 |  |  |  |  |  | 35,985 |  | 33,565 |  | 31,366 |  |  |
Business Combination, Bargain Purchase, Gain Recognized, Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 233 |  | 0 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,084 |  | 3,876 |  | 1,196 |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 | [3] | $ 0 | [4] | 558 | [5],[6] |  |
Wind Assets [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Non-Financial Commitment1 | MW |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 40 |  |  |  |  |  |  |
Exelon Corporation Affiliate [Member] | Commitment Adjustment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | $ 5 |  |  |  |  |  |  |  |  |  |  |  |  | $ 5 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Wind Assets [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Non-Financial Commitment1 | MW |  |  |  |  |  |  |  |  |  | 40 |  |  |  |  |  |  |  |  |  |  |  |  | 120 |  | 40 |  |  |  |  |
Delmarva Power & Light Company [Member] | Remaining Commitment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | $ 12 |  |  |  |  |  |  |  |  |  |  |  |  | $ 12 |  |  |  |  |  |  |
Exelon Consolidations [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 508 |  |  |  |  |  |  |  |  |  |  |  |  | 508 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Rate Bill Credits [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 259 |  |  |  |  |  |  |  |  |  |  |  |  | 259 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Other1 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 29 |  |  |  |  |  |  |  |  |  |  |  |  | 29 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Energy Efficiency Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 117 |  |  |  |  |  |  |  |  |  |  |  |  | 117 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Charitable Contributions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 50 |  |  |  |  |  |  |  |  |  |  |  |  | 50 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Delivery System Modernization [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 22 |  |  |  |  |  |  |  |  |  |  |  |  | 22 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Green Sustainability Fund [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 14 |  |  |  |  |  |  |  |  |  |  |  |  | 14 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Workforce Development [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 17 |  |  |  |  |  |  |  |  |  |  |  |  | 17 |  |  |  |  |  |  |
Exelon Consolidations [Member] | Remaining Commitment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 128 |  |  |  |  |  |  |  |  |  |  |  |  | 128 |  |  |  |  |  |  |
Pepco Holdings [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  |  |  |  |  |  |  | $ 7,142 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 4,670 |  | $ 4,829 |  | 3,785 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 453 |  | $ 364 |  | (66) |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |  |  |  |  |  |  |  |  | $ 4,005 |  |  |  |  |  |  |  |  |  | $ 4,005 |  |  |  |  |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Other Solar Projects [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Non-Financial Commitment1 | MW |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 27 |  | 37 |  |  |  |  |
Pepco Holdings LLC [Member] | Wind Assets [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Non-Financial Commitment1 | MW |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Commitments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 513 |  |  | $ 513 | $ 513 |  |  |  |  | 513 |  |  |
Pepco Holdings LLC [Member] | Remaining Commitment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 92 |  |  |  |  |  |  |  |  |  |  |  |  | $ 92 |  |  |  |  |  |  |
ConEdison Solutions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  |  |  |  |  | $ 257 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net Working Capital |  |  |  |  |  |  | $ 204 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Oyster Creek [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets held for sale |  |  |  |  |  |  |  |  |  | 897 |  |  |  |  |  |  |  |  |  |  |  |  | 897 |  |  |  |  |  |  |
Baltimore Gas and Electric Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  | 0 |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 | [1],[7] | $ 4 | [1],[7] | (1) |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 799 | 731 | 662 | 977 | 813 | 738 | 674 | 951 |  |  |  |  |  | 3,169 |  | 3,176 |  | 3,233 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  | 71 | 63 | 51 | 128 | 76 | 62 | 45 | 125 |  |  |  |  |  | 313 |  | 307 |  | 294 |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [3] | 0 | [4] | 0 | [5],[6] |  |
Exelon Generation Co L L C [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets held for sale |  |  |  |  |  |  |  |  |  | 904 |  |  |  | 0 |  |  |  |  |  |  |  |  | 904 |  | 0 |  |  |  |  |
Liabilities held for sale |  |  |  |  |  |  |  |  |  | 777 |  |  |  | 0 |  |  |  |  |  |  |  |  | 777 |  | 0 |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  | 203 | 84 |  |  |  |  |  |  |  |  | $ 138 |  |  | 0 |  |  |  | 0 |  |  |
Deconsolidation, Gain (Loss), Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 213 |  | 0 |  |  |
Proceeds from Divestiture of Businesses |  |  |  | $ 87 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Membership interest |  |  |  |  |  |  |  |  |  | 9,518 |  |  |  | 9,357 |  |  |  |  |  |  |  |  | 9,518 |  | 9,357 |  |  |  |  |
Business Combination, Contingent Consideration, Asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 163
Payments to Acquire Businesses, Gross |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 154 |  | 208 |  | 293 |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 | [1] | 22 | [1] | 37 |  |  |
Line of credit facility, maximum borrowing capacity |  |  |  |  |  |  |  |  |  | 200 |  | 45 |  |  |  |  |  |  |  |  |  |  | 200 |  |  |  |  |  |  |
Gain (Loss) on Disposition of Property Plant Equipment |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |  |  |  |  | 69 |  |  |
Proceeds from Sale of Productive Assets |  |  |  |  |  |  |  | $ 37 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 5,069 | 5,278 | 4,579 | 5,512 | 4,657 | 4,750 | 4,216 | 4,878 |  |  |  |  |  | 20,437 |  | 18,500 |  | 17,757 |  |  |
Business Combination, Bargain Purchase, Gain Recognized, Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  | 233 |  | 0 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 443 |  | 2,798 |  | 550 |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [3] | 0 | [4] | 53 | [5],[6] |  |
Asset Impairment Charges |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 23 |  |  |  |  |  |  |  |  |  |  |  |
Exelon Generation Co L L C [Member] | FirstEnergy [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  | $ 140 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exelon Generation Co L L C [Member] | Handley [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  | $ 62 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Exelon Generation Co L L C [Member] | Fitzpatrick [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred |  |  |  |  |  | $ 289 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 289 |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 110 |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 60 |  |  |  |  |  |  |  |  |  |  | 60 |  |  |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 57 |  |  |  |  |
Business Combination, Consideration Transferred, Other |  |  |  |  |  | 179 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 54 |  |  |  |  |
Business Combination, Bargain Purchase, Gain Recognized, Amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 233 |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent |  |  |  |  |  |  |  |  |  |  |  |  |  | 149 |  |  |  |  |  |  |  |  |  |  | 149 |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 114 |  |  |  |  |  |  |  |  |  |  | 114 |  |  |  |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities |  |  |  |  |  |  |  |  |  |  |  |  |  | 444 |  |  |  |  |  |  |  |  |  |  | 444 |  |  |  |  |
Total net assets |  |  |  |  |  |  |  |  |  |  |  |  |  | 522 |  |  |  |  |  |  |  |  |  |  | 522 |  |  |  |  |
Exelon Generation Co L L C [Member] | Fitzpatrick [Member] | Cash and Cash Equivalents [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred |  |  |  |  |  | 110 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payments to Acquire Businesses, Gross |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 125 |  |  |  |  |
Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Membership interest |  |  |  |  |  |  |  |  |  | 9,220 |  |  |  | 8,835 |  |  |  |  |  |  |  |  | 9,220 |  | 8,835 |  |  |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [1],[7] | (6) | [1],[7] | 28 |  |  |
Other Commitment |  |  |  |  |  | $ 444 |  |  |  |  |  |  |  |  |  |  | 444 |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 1,117 | 1,361 | 1,076 | 1,251 | 1,121 | 1,310 | 1,074 | 1,175 |  |  |  |  |  | 4,805 |  | 4,679 |  |  |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 398 |  | 362 |  |  |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 | [3] | (8) | [4] |  |  |  |
Impairment of Long-Lived Assets to be Disposed of |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 25 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Predecessor [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |
Business Combination, Integration Related Costs | [7] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 29 |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,153 |  |  |  |  |  |  |  |  |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 19 |  |  |  |  |  |  |  |  |  |  |
Noncash Merger Related Costs | [5],[6] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Successor [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2 | 20 |  |  |  |  |  |  |
Business Combination, Contingent Consideration, Asset |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 235
Business Combination, Integration Related Costs | [7] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 69 | 0 |  | (18) | [1] |  |  |  |
Business Combination, Consideration Transferred, Other |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 59 |  |  |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3,643 |  |  | 4,679 |  |  |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (61) | (61) |  |  |  |  |  |  |  |
Noncash Merger Related Costs | [5],[6] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 317 |  |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 320 |  |  |  |  |  |  |  |  |  |  |  |  | 320 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Rate Bill Credits [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 264 |  |  |  |  |  |  |  |  |  |  |  |  | 264 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Other1 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 6 |  |  |  |  |  |  |  |  |  |  |  |  | 6 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Energy Efficiency Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Charitable Contributions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 50 |  |  |  |  |  |  |  |  |  |  |  |  | 50 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Delivery System Modernization [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Green Sustainability Fund [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Pepco Holdings LLC [Member] | Pepco Holdings LLC [Member] | Workforce Development [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 22 |  |  |  | 0 |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 531 | 628 | 523 | 557 | 510 | 604 | 514 | 530 |  |  |  |  |  | 2,239 |  | 2,158 |  | 2,186 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  | 36 | 89 | 54 | 31 | 17 | 87 | 43 | 58 |  |  |  |  |  | 210 |  | 205 |  | 42 |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [3] | (6) | [4] | 125 | [5],[6] |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,100
Fresh-Start Adjustment, Increase (Decrease), Goodwill |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 400
Potomac Electric Power Company [Member] | Commitments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Additional Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 73 |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 120 |  |  |  |  |  |  |  |  |  |  |  |  | 120 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Rate Bill Credits [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 91 |  |  |  |  |  |  |  |  |  |  |  |  | 91 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Other1 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Energy Efficiency Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Charitable Contributions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 28 |  |  |  |  |  |  |  |  |  |  |  |  | 28 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Delivery System Modernization [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Green Sustainability Fund [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Potomac Electric Power Company [Member] | Pepco Holdings LLC [Member] | Workforce Development [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (1) |  |  |  | 1 |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [1],[7] | (7) | [1],[7] | 20 |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 331 | 328 | 289 | 384 | 330 | 327 | 282 | 362 |  |  |  |  |  | 1,332 |  | 1,300 |  | 1,277 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  | 30 | 33 | 26 | 31 | 14 | 31 | 19 | 57 |  |  |  |  |  | 120 |  | 121 |  | (9) |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5 | [3] | (2) | [4] | 82 | [5],[6] |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,400
Fresh-Start Adjustment, Increase (Decrease), Goodwill |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300
Delmarva Power & Light Company [Member] | Commitments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Additional Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 46 |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 89 |  |  |  |  |  |  |  |  |  |  |  |  | 89 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Rate Bill Credits [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 72 |  |  |  |  |  |  |  |  |  |  |  |  | 72 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Commitment Adjustment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 5 |  |  |  |  |  |  |  |  |  |  |  |  | 5 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Other1 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 5 |  |  |  |  |  |  |  |  |  |  |  |  | 5 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Energy Efficiency Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Charitable Contributions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 12 |  |  |  |  |  |  |  |  |  |  |  |  | 12 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Delivery System Modernization [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Green Sustainability Fund [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Delmarva Power & Light Company [Member] | Pepco Holdings LLC [Member] | Workforce Development [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Asset Retirement Obligation, Revision of Estimate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (1) |  |  |  | 2 |  |  |
Business Combination, Integration Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [1],[7] | (6) | [1],[7] | 19 |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 254 | 406 | 265 | 310 | 271 | 370 | 270 | 275 |  |  |  |  |  | 1,236 |  | 1,186 |  | 1,257 |  |  |
Net income (Loss) |  |  |  |  |  |  |  |  |  | (1) | $ 61 | 8 | $ 7 | $ 0 | $ 41 | 8 | $ 28 |  |  |  |  |  | 75 |  | 77 |  | (42) |  |  |
Noncash Merger Related Costs |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 0 | [3] | $ 0 | [4] | $ 110 | [5],[6] |  |
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 500
Fresh-Start Adjustment, Increase (Decrease), Goodwill |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ (700)
Atlantic City Electric Company [Member] | Commitments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Additional Capital |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 49 |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 111 |  |  |  |  |  |  |  |  |  |  |  |  | 111 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Rate Bill Credits [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 101 |  |  |  |  |  |  |  |  |  |  |  |  | 101 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Other1 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Energy Efficiency Program [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Charitable Contributions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |  |  |  |  |  |  | 10 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Delivery System Modernization [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Green Sustainability Fund [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Atlantic City Electric Company [Member] | Pepco Holdings LLC [Member] | Workforce Development [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |  |  |  |  |  |  | 0 |  |  |  |  |  |  |
Exelon Corporation Affiliate [Member] | Other commitments [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Other Commitment |  |  |  |  |  |  |  |  |  | $ 83 |  |  |  |  |  |  |  |  |  |  |  |  | $ 83 |  |  |  |  |  |  |
Electricity Generation Plant, Non-Nuclear [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment of Long-Lived Assets to be Disposed of |  |  |  |  |  |  |  |  |  |  |  | $ 41 |  |  |  | $ 460 |  |  |  | $ 460 |  |  |  |  |  |  |  |  |  |
[1] | The costs incurred are classified primarily within Operating and maintenance expense in the Registrants’ respective Consolidated Statements of Operations and Comprehensive Income, with the exception of the financing costs, which are included within Interest expense. Costs do not include merger commitments discussed above.
[2] | Excludes $135 million of credit facility agreements arranged at minority and community banks at Generation, ComEd, PECO, BGE, Pepco, DPL and ACE with aggregate commitments of $49 million, $33 million, $34 million, $5 million, $5 million, $5 million and $5 million, respectively. These facilities expire on October 11, 2019. These facilities are solely utilized to issue letters of credit. As of December 31, 2018, letters of credit issued under these facilities totaled $5 million and $2 million for Generation and BGE, respectively.
[3] | See Note 5 - Mergers, Acquisitions and Dispositions for additional information.
[4] | See Note 5 - Mergers, Acquisitions and Dispositions for additional information.
[5] | Excludes $5 million of forgiveness of Accounts receivable related to merger commitments recorded in connection with the PHI Merger, the balance is included within Provision for uncollectible accounts.
[6] | See Note 5 - Mergers, Acquisitions and Dispositions for additional information.
[7] | (b)For the year ended December 31, 2017, includes deferrals of previously incurred integration costs as regulatory assets of $24 million, $8 million, $8 million, and $8 million at PHI, Pepco, DPL and ACE, respectively. For the year ended December 31, 2016, includes deferrals of previously incurred integration costs as regulatory assets of $8 million, $6 million, $11 million and $4 million at ComEd, BGE, Pepco and DPL, respectively. For the Successor period March 24, 2016 to December 31, 2016, includes deferrals of previously incurred integration costs as regulatory assets of $16 million at PHI. See Note 4 - Regulatory Matters for additional information.

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