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ASSET RETIREMENT OBLIGATIONS - Narrative (Details) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 MW
Changes to the asset retirement obligations |  |  |
Beginning Balance | $ 856 | $ 812 |
Liabilities settled | (744) | (2) |
Accretion | 47 | 46 |
Ending Balance | 159 | 856 |
Noncurrent liabilities - held for sale (Note 15) | 0 | 691 |
TMI-2 |  |  |
Changes to the asset retirement obligations |  |  |
Noncurrent liabilities - held for sale (Note 15) |  | $ 691 |
Decrease in asset retirement obligation | $ 726 |  |
Pleasants Power Station | Purchase Agreement with Subsidiary of LS Power | AE Supply |  |  |
Asset Retirement Obligations [Line Items] |  |  |
Plant generation capacity (in MW's) | MW |  |  | 1,300

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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://fasb.org/us-gaap/role/ref/legacyRef -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 + Details
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