XML 85 R62.htm IDEA: XBRL DOCUMENT
v3.24.2

Asset Retirement Obligations (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Sep. 30, 2023
Asset Retirement Obligations |  |  |
Asset Retirement Obligation, Period Increase (Decrease) | $ 3,300 |  |
Amortization and Depreciation of Decontaminating and Decommissioning Assets | 141 |  |
Asset Retirement Obligation, Beginning Balance | 7,489 |  |
Settlements | (190) |  |
Asset Retirement Obligation, Revision of Estimate | 136 |  |
Asset Retirement Obligation, Liabilities Incurred | 3,136 |  |
Accretion Expense, Including Asset Retirement Obligations | 200 |  |
Asset Retirement Obligation, Ending Balance | 10,771 |  |
Current portion of ARO | (283) |  | $ (272)
Revision in ARO estimate | (164) |  |
Gallatin Fossil Plant |  |  |
Asset Retirement Obligations |  |  |
Change in closure liabilities |  | $ 231 |
Cumberland Fossil Plant |  |  |
Asset Retirement Obligations |  |  |
Change in closure liabilities | 76 |  |
Nuclear |  |  |
Asset Retirement Obligations |  |  |
Asset Retirement Obligation, Beginning Balance | 3,808 |  |
Settlements | (4) |  |
Asset Retirement Obligation, Revision of Estimate | (161) |  |
Asset Retirement Obligation, Liabilities Incurred |  | $ 0 |
Accretion Expense, Including Asset Retirement Obligations | 128 |  |
Asset Retirement Obligation, Ending Balance | 3,771 |  |
Non-nuclear |  |  |
Asset Retirement Obligations |  |  |
Asset Retirement Obligation, Beginning Balance | 3,681 |  |
Settlements | (186) |  |
Asset Retirement Obligation, Revision of Estimate | 297 |  |
Asset Retirement Obligation, Liabilities Incurred | 3,136 |  |
Accretion Expense, Including Asset Retirement Obligations | 72 |  |
Asset Retirement Obligation, Ending Balance | $ 7,000 |  |

X
- Definition Change in closure liabilities + References No definition available. + Details
Name: | tve_ChangeInClosureLiabilities
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reconciliation of Asset Retirement Obligations [Line Items] + References No definition available. + Details
Name: | tve_ReconciliationOfAssetRetirementObligationsLineItems
Namespace Prefix: | tve_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revision in ARO estimate + References No definition available. + Details
Name: | tve_RevisionInAROEstimate
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of accretion expense, which includes, but is not limited to, accretion expense from asset retirement obligations, environmental remediation obligations, and other contingencies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481879/410-20-45-1 + Details
Name: | us-gaap_AccretionExpenseIncludingAssetRetirementObligations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The current period expense charged against earnings on decontaminating and decommissioning of facilities used in the normal conduct of business and not intended for resale to allocate or recognize the cost of the assets over their useful lives. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 230 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 + Details
Name: | us-gaap_AmortizationAndDepreciationOfDecontaminatingAndDecommissioningAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 25 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481999/410-20-25-4 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Current portion of 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/2009/role/commonPracticeRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of asset retirement obligations incurred during the period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesIncurred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- 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. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesSettled
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in asset retirement obligations. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- 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/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c)(4) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 + Details
Name: | us-gaap_AssetRetirementObligationRevisionOfEstimate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | tve_PlantAxis=tve_GallatinFossilPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | tve_PlantAxis=tve_CumberlandFossilPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | tve_ReconciliationOfAssetRetirementObligationLiabilityAxis=tve_NuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | tve_ReconciliationOfAssetRetirementObligationLiabilityAxis=tve_NonNuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |