XML 106 R82.htm IDEA: XBRL DOCUMENT v3.10.0.1

Revenue Energy Prepayment Agreement (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2018
Long-term Contract for Purchase of Electric Power [Line Items]
Proceeds from Maturities, Prepayments and Calls of Other Investments	$ 1,500
Other Significant Noncash Transaction, Value of Consideration Given	$ 10	$ 25	$ 100
Revenue Recognition, Revenue Reductions [Policy Text Block]	141	137
Discount to Revenue [Member]
Long-term Contract for Purchase of Electric Power [Line Items]
Other Significant Noncash Transaction, Value of Consideration Given	$ 4	$ 11

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_LongTermContractForPurchaseOfElectricPowerLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The value of the noncash (or part noncash) consideration given (for example, liability, equity) in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586

+ Details

Name:	us-gaap_OtherSignificantNoncashTransactionValueOfConsiderationGiven1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The cash inflow associated with the maturity (principal being due), prepayment and call (request of early payment) of other investments not otherwise defined in the taxonomy.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromMaturitiesPrepaymentsAndCallsOfOtherInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Disclosure of accounting policy of sales arrangements for goods or services that reduce the amount of revenue recognized for example sales returns, allowances, incentives, rebates, discounts and loyalty programs.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790

+ Details

Name:	us-gaap_RevenueRecognitionRevenueReductions
Namespace Prefix:	us-gaap_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	tve_DiscounttoRevenueAxis=tve_DiscounttoRevenueMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: