XML 175 R87.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Risk Management Activities and Derivative Transactions Counterparty Credit Risk (Details) | 12 Months Ended
--- | ---
Sep. 30, 2022
Derivative |
Two Largest Customer Percentage of Total Operating Revenue | 17.00%
Moody's, A1 Rating |
Derivative |
Banking Counterparties Credit Rating | A2
Natural Gas Banking Counterparties Credit Rating | A1
Moody's, B1 Rating |
Derivative |
Natural Gas Banking Counterparties Credit Rating | B1

X
- Definition Banking Counterparties Credit Rating + References No definition available. + Details
Name: | tve_BankingCounterpartiesCreditRating
Namespace Prefix: | tve_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Natural Gas Banking Counterparties Credit Rating + References No definition available. + Details
Name: | tve_NaturalGasBankingCounterpartiesCreditRating
Namespace Prefix: | tve_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Two Largest Customer Percentage of Total Operating Revenue + References No definition available. + Details
Name: | tve_TwoLargestCustomerPercentageOfTotalOperatingRevenue
Namespace Prefix: | tve_
Data Type: | dtr-types:percentItemType
Balance Type: | na
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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysA1RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CreditRatingMoodysAxis=srt_MoodysB1RatingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |