XML 222 R115.htm IDEA: XBRL DOCUMENT
v3.21.2

Commitments and Contingencies - Table (Details) $ in Millions | Sep. 30, 2021 USD ($) megawatts | Sep. 30, 2020 USD ($) | Sep. 30, 2019 USD ($)
--- | --- | --- | ---
Obligations |  |  |  |
Megawatts provided under transmission obligations | megawatts |  | 2,450 |  |
Accrual for Environmental Loss Contingencies, Gross |  | $ 18 | $ 14 |
Estimated future decommissioning cost | [1] | 7,002 | 6,785 | $ 5,616
CT and QTE outstanding leaseback obligation |  | 25 | 223 |
Nuclear |  |  |  |
Obligations |  |  |  |
Estimated future decommissioning cost |  | $ 3,428 | $ 3,278 | $ 3,136
[1] | (1) Includes $266 million a nd $345 million at September 30, 2021 and 2020, respectively, in Current liabilities. TVA implemented revised depreciation rates during the first quarter of 2022 applicable to its completed plant as a result of the completion of a new depreciation study. The study includes a decline in the service life estimates of TVA’s coal-fired plants based on current planning assumptions to potentially retire the remainder of the coal-fired fleet by 2035. As a result of the accelerated retirements reflected in the depreciation study, TVA performed an assessment of the assumptions used in the timing of cash flows related to its non-nuclear AROs. Based on the assessment, TVA identified changes to its projections of timing of certain asset retirement processes, that will be recorded in 2022.

X
- Definition The outstanding leaseback obligations related to combustion turbine units and qualified technological equipment and software. + References No definition available. + Details
Name: | tve_CtAndQteOutstandingLeasebackObligation
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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 Undiscounted amount of the accrual for environmental loss contingencies. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13207-110859 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 5.Y.Q1) -URI http://asc.fasb.org/extlink&oid=27011672&loc=d3e149879-122751 + 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://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
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: |