Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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The aggregate amount of write-downs for impairments recognized during the period for long-lived assets held for abandonment, exchange or sale.

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Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

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Subsequent Event (Details) - USD ($) $ in Millions		3 Months Ended
Subsequent Event (Details) - USD ($) $ in Millions	Jul. 09, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Subsequent Event [Line Items]
Decommissioning Fund Investments			$ 13,110	$ 13,272
Exelon Generation Co L L C [Member]
Subsequent Event [Line Items]
Decommissioning Fund Investments			13,110	$ 13,272
Subsequent Event [Member] \| Oyster Creek [Member]
Subsequent Event [Line Items]
Decommissioning Fund Investments			$ 980
FirstEnergySolutionsCorporation [Member] \| Subsequent Event [Member] \| Exelon Generation Co L L C [Member]
Subsequent Event [Line Items]
Business Combination, Consideration Transferred	$ 140
Minimum [Member] \| Subsequent Event [Member] \| Oyster Creek [Member]
Subsequent Event [Line Items]
Impairment of Long-Lived Assets to be Disposed of		$ 60
Maximum [Member] \| Subsequent Event [Member] \| Oyster Creek [Member]
Subsequent Event [Line Items]
Impairment of Long-Lived Assets to be Disposed of		$ 100