XML 114 R86.htm IDEA: XBRL DOCUMENT
v3.21.2

Plant Closures (Details) - USD ($) | 3 Months Ended | 9 Months Ended | 24 Months Ended
--- | --- | --- | ---
Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020 | Mar. 31, 2021
Property, Plant and Equipment [Line Items] |  |  |  |  |
Accelerated depreciation | $ 35,000,000 | $ 34,000,000 | $ 102,000,000 | $ 350,000,000 | $ 1,100,000,000

X
- Definition Accelerated depreciation + References No definition available. + Details
Name: | tve_AcceleratedDepreciation
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration