XML 193 R107.htm IDEA: XBRL DOCUMENT
v3.20.2

Benefit Plans Expected Amortization of Regulatory Assets in Next Fiscal Year (Details) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2020 USD ($)
Defined Benefit Plan Disclosure |
Prior service cost (credit) | $ (115)
Net actuarial loss | 459
Defined Benefit Plan Amortization From Regulatory Assets Of Amounts Capitalized due to Actions of Regulatory | 28
Pension Benefits |
Defined Benefit Plan Disclosure |
Prior service cost (credit) | (97)
Net actuarial loss | 447
Defined Benefit Plan Amortization From Regulatory Assets Of Amounts Capitalized due to Actions of Regulatory | 28
Other Post-retirement Benefits |
Defined Benefit Plan Disclosure |
Prior service cost (credit) | (18)
Net actuarial loss | 12
Defined Benefit Plan Amortization From Regulatory Assets Of Amounts Capitalized due to Actions of Regulatory | $ 0

X
- Definition Defined Benefit Plan Amortization From Regulatory Assets Of Amounts Capitalized due to Actions of Regulatory + References No definition available. + Details
Name: | tve_DefinedBenefitPlanAmortizationFromRegulatoryAssetsOfAmountsCapitalizedDueToActionsOfRegulatory
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amounts in regulatory assets related to gains and losses that are not recognized immediately and are expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented. + References No definition available. + Details
Name: | tve_DefinedBenefitPlanAmortizationFromRegulatoryAssetsOfNetGainsLosses
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amounts in regulatory assets related to prior service cost or credit expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented. + References No definition available. + Details
Name: | tve_DefinedBenefitPlanAmortizationFromRegulatoryAssetsOfNetPriorServiceCostCredit
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |