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Asset Retirement Obligations (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 27, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017
FES | Beaver Valley, Davis-Besse and Perry Power Plants
Asset Retirement Obligations [Line Items]
Asset retirement obligation	$ 787			$ 713
FES | Beaver Valley Unit 2
Asset Retirement Obligations [Line Items]
ARO transferred		$ 73
FES | Perry Power Plant Unit 1
Asset Retirement Obligations [Line Items]
ARO transferred			$ 28
NG | Beaver Valley Unit 2
Asset Retirement Obligations [Line Items]
ARO transferred		$ 49
Ownership percentage				100.00%

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- Definition

Asset Retirement Obligations.

+ References

No definition available.

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- Definition

Asset Retirement Obligations, Transfers

+ References

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- Definition

Public Utilities, Plant Ownership Percentage

+ References

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- Definition

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

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