XML 112 R78.htm IDEA: XBRL DOCUMENT v3.25.1

Risk Management Activities and Derivative Transactions Counterparty Credit Risk (Details) $ in Millions	6 Months Ended
	Mar. 31, 2025 USD ($) Customers	Mar. 31, 2024	Sep. 30, 2024 USD ($)
Derivative
Accounts Receivable, before Allowance for Credit Loss, Current | $	$ 1,604		$ 1,683
Two Largest Customer Percentage of Total Operating Revenue	1500.00%	1500.00%
Moody's, A1 Rating [Member]
Derivative
Natural Gas Banking Counterparties Credit Rating	A1
Moody's, B1 Rating [Member]
Derivative
Natural Gas Banking Counterparties Credit Rating	B1
Moody's, A2 Rating
Derivative
Banking Counterparties Credit Rating	A2
Credit of Customers
Derivative
Number of customers that represent the percent of sales	2
Number of customers that represent the percent of sales	2

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

Number of customers that represent the percent of sales

+ References

No definition available.

+ Details

Name:	tve_Numberofcustomersthatrepresentthepercentofsales
Namespace Prefix:	tve_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

This concept explains the total percentage of operating revenue provided by the two largest customers.

+ References

No definition available.

+ Details

Name:	tve_TwoLargestCustomerPercentageOfTotalOperatingRevenue
Namespace Prefix:	tve_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration

X

- 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 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481990/310-10-45-2

Reference 2: 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))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/exampleRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483467/210-10-45-1

+ Details

Name:	us-gaap_AccountsReceivableGrossCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480237/815-40-50-5

+ 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:

X

- Details

Name:	srt_CreditRatingMoodysAxis=srt_MoodysA2RatingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=tve_CreditOfCustomersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: