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v3.10.0.1

Income Taxes Deferred Tax Revision (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2017 | Dec. 31, 2018
Regulatory Liabilities |  | $ 10,388 | $ 10,203
Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability | [1] | 8,624 |
Regulatory Liabilities | [2] | 7,315 |
Deferred Income Tax Expense (Benefit) | [1] | 1,309 |
Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 3,040 |
Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 1,694 |
Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 4,734 |
Exelon Generation Co L L C [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 1,895 |
Deferred Income Tax Expense (Benefit) |  | 1,895 |
Commonwealth Edison Co [Member] |  |  |
Regulatory Liabilities |  | 6,577 | 6,343
Commonwealth Edison Co [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 2,819 |
Regulatory Liabilities | [2] | 2,818 |
Deferred Income Tax Expense (Benefit) |  | 1 |
Commonwealth Edison Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 1,400 |
Commonwealth Edison Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 573 |
Commonwealth Edison Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 1,973 |
PECO Energy Co [Member] |  |  |
Regulatory Liabilities |  | 690 | 596
PECO Energy Co [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 1,407 |
Regulatory Liabilities | [2] | 1,394 |
Deferred Income Tax Expense (Benefit) |  | 13 |
PECO Energy Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities | [3] | 533 |
PECO Energy Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities | [3] | 43 |
PECO Energy Co [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities | [3] | 576 |
Baltimore Gas and Electric Company [Member] |  |  |
Regulatory Liabilities |  | 1,163 | 1,269
Baltimore Gas and Electric Company [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 1,120 |
Regulatory Liabilities | [2] | 1,124 |
Deferred Income Tax Expense (Benefit) |  | (4) |
Baltimore Gas and Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 459 |
Baltimore Gas and Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 324 |
Baltimore Gas and Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 783 |
Pepco Holdings LLC [Member] |  |  |
Regulatory Liabilities |  | 1,928 | 1,948
Pepco Holdings LLC [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 1,944 |
Regulatory Liabilities | [2] | 1,979 |
Deferred Income Tax Expense (Benefit) |  | (35) |
Pepco Holdings LLC [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 648 |
Pepco Holdings LLC [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 754 |
Pepco Holdings LLC [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 1,402 |
Potomac Electric Power Company [Member] |  |  |
Regulatory Liabilities |  | 832 | 829
Potomac Electric Power Company [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 968 |
Regulatory Liabilities | [2] | 976 |
Deferred Income Tax Expense (Benefit) |  | (8) |
Potomac Electric Power Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 299 |
Potomac Electric Power Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 391 |
Potomac Electric Power Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 690 |
Delmarva Power & Light Company [Member] |  |  |
Regulatory Liabilities |  | 635 | 665
Delmarva Power & Light Company [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 540 |
Regulatory Liabilities | [2] | 545 |
Deferred Income Tax Expense (Benefit) |  | (5) |
Delmarva Power & Light Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 195 |
Delmarva Power & Light Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 194 |
Delmarva Power & Light Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | 389 |
Atlantic City Electric Company [Member] |  |  |
Regulatory Liabilities |  | 422 | $ 420
Atlantic City Electric Company [Member] | Remeasurement Of Deferred Income Taxes DueTo Tax Reform [Member] |  |  |
Increase (Decrease) in Other Deferred Liability |  | 456 |
Regulatory Liabilities | [2] | 458 |
Deferred Income Tax Expense (Benefit) |  | (2) |
Atlantic City Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To IRS Normalization Rules [Member] |  |  |
Regulatory Liabilities |  | 153 |
Atlantic City Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers Subject To Rate Regulator Determinations [Member] |  |  |
Regulatory Liabilities |  | 170 |
Atlantic City Electric Company [Member] | Net Regulatory Liabilities Associated With Ultimate Settlement To Customers [Member] |  |  |
Regulatory Liabilities |  | $ 323 |
[1] | Amounts do not sum across due to deferred tax adjustments recorded at the Exelon Corporation parent company, primarily related to certain employee compensation plans.
[2] | Reflects the net regulatory liabilities recorded on a pre-tax basis before taking into consideration the income tax benefits associated with the ultimate settlement with customers.
[3] | Given the regulatory treatment of income tax benefits related to electric and gas distribution repairs, PECO was in an overall net regulatory asset position as of December 31, 2017 after recording the impacts related to the TCJA. As a result, the amount of customer benefits resulting from the TCJA subject to the discretion of PECO's rate regulators are lower relative to the other Utility Registrants.

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