XML 188 R118.htm IDEA: XBRL DOCUMENT
v3.24.3

Commitments and Contingencies - Table (Details) $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2024 USD ($) megawatts | Sep. 30, 2023 USD ($) | Sep. 30, 2022 USD ($)
Obligations |  |  |  |
Megawatts provided under transmission obligations | megawatts |  | 4,750 |  |
Accrual for Environmental Loss Contingencies, Gross |  | $ 15 | $ 16 |
Estimated future decommissioning cost | [1] | $ 10,806 | 7,489 | $ 7,162
Remaining terms of the transmission obligations, high end of range |  | 5 years |  |
Nuclear |  |  |  |
Obligations |  |  |  |
Estimated future decommissioning cost |  | $ 3,814 | $ 3,808 | $ 3,643
[1] | (1) Includes $283 million and $272 million at September 30, 2024 and 2023, respectively, in Current liabilities.

X
- Definition Megawatts provided under transmission obligations + References No definition available. + Details
Name: | tve_Megawattsprovidedundertransmissionobligations
Namespace Prefix: | tve_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Remaining terms of the transmission obligations, high end of range + References No definition available. + Details
Name: | tve_RemainingTermsOfTheTransmissionObligationsHighEndOfRange
Namespace Prefix: | tve_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Undiscounted amount of the accrual for environmental loss contingencies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480102/450-20-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481931/410-30-50-7 + Details
Name: | us-gaap_AccrualForEnvironmentalLossContingenciesGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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