XML 222 R132.htm IDEA: XBRL DOCUMENT
v3.23.3

Revenue Economic Development Incentives (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2023 | Sep. 30, 2022 | Sep. 30, 2021
Revenue from Contract with Customer [Abstract] |  |  |
Revenues | $ 330 | $ 328 | $ 315
Unpaid economic incentives | $ (188) | $ (187) |

X
- Definition Economic incentives + References No definition available. + Details
Name: | tve_Economicincentives
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unpaid economic incentives + References No definition available. + Details
Name: | tve_UnpaidEconomicIncentives
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_RevenueFromContractWithCustomerAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration