Fair value as of the balance sheet date of forward contract derivative assets.

No definition available.

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Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount, before allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3)(a)(1))
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Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
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-Topic 310
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-Publisher FASB
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+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of foreign currency exchange rate derivatives held by the entity at the reporting date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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-URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A

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- 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

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- Details

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- Details

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- Details

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Risk Management Activities and Derivative Transactions Offsetting for Derivative Liabilities (Details) $ in Millions	Mar. 31, 2024 USD ($)	Sep. 30, 2023 USD ($)	Jun. 30, 2023 Bond_issues
Offsetting Liabilities [Line Items]
Number of currency swaps outstanding \| Bond_issues			2
Accounts Receivable, before Allowance for Credit Loss, Current	$ 1,379	$ 1,627
Amount of letters of credit outstanding	6
Forward Contract Derivative Asset, at Fair Value	5	11
Letter of Credit
Offsetting Liabilities [Line Items]
Amount of letters of credit outstanding	516	535
Interest Swap Collateral
Offsetting Liabilities [Line Items]
Amount of letters of credit outstanding	485
Fair Value, Inputs, Level 2
Offsetting Liabilities [Line Items]
Forward Contract Derivative Asset, at Fair Value	$ 5	$ 11