Asset Retirement Obligation Period Increase Decrease.

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- Definition

Asset Retirement Obligations.

+ References

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- Definition

Asset Retirement Obligations, Transfers

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- Definition

Public Utilities, Plant Ownership Percentage

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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

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Asset Retirement Obligation
-URI http://asc.fasb.org/extlink&oid=6505190

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- Definition

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

+ 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)(3)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848

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- Definition

Carrying amount of an asset that is legally restricted for purposes of settling an asset retirement obligation.

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- Definition

Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset.

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- Definition

Amount of increase (decrease) in the asset retirement obligation from changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation.

+ 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)(4)
-URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 410
-SubTopic 20
-Section 35
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6392603&loc=d3e7123-110846

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- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Asset Retirement Obligations (Details) - USD ($) $ in Millions			12 Months Ended
	Jun. 30, 2016	May 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligations [Line Items]
Nuclear plant decommissioning trusts			$ 2,514	$ 2,282
Fair value of decommissioning trust assets				2,282
Changes to the asset retirement obligations
Beginning Balance			1,410	1,387
Liabilities settled			(27)	(13)
Accretion			95	92
Revisions in estimated cash flows			(4)	56
Ending Balance			1,482	1,410
FES
Asset Retirement Obligations [Line Items]
Nuclear plant decommissioning trusts			1,552	1,327
Fair value of decommissioning trust assets				1,327
Changes to the asset retirement obligations
Beginning Balance			831	841
Liabilities settled			(18)	(8)
Accretion			56	55
Revisions in estimated cash flows			(32)	57
Ending Balance			901	831
FES \| Beaver Valley, Davis-Besse and Perry Nuclear Generating Stations
Changes to the asset retirement obligations
Ending Balance			713
FES \| Davis-Besse and Perry Nuclear Generating Stations
Changes to the asset retirement obligations
Revisions in estimated cash flows				$ 57
NG \| Perry Power Plant Unit 1
Changes to the asset retirement obligations
Asset retirement obligations transfers			$ 28
Plant ownership percentage	100.00%	100.00%