XML 53 R72.htm IDEA: XBRL DOCUMENT v3.2.0.727

Fair Value Measurements Fair Value Measurements Using Significant Unobservable Inputs (Details) tons-per-year in Billions		3 Months Ended		9 Months Ended		12 Months Ended
		Jun. 30, 2015 USD ($) tons-per-year	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) tons-per-year	Jun. 30, 2014 USD ($)	Sep. 30, 2014 USD ($) Contracts tons-per-year	Mar. 31, 2015 USD ($)	Mar. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)
ASSETS
Commodity contract derivatives		$ 3,000,000		$ 3,000,000		$ 1,000,000
Liabilities
Commodity contract derivatives		128,000,000		128,000,000		$ 97,000,000
Number of contracts | Contracts						2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amount of gain (loss) recognized in income		$ 0		$ 0
Maximum
ASSETS
Fair value inputs, counterparty credit risk	[1]					5.00%
Fair value measurements tons per year | tons-per-year		1.0		1.0		1.1
Price per ton		$ 103.41		$ 103.41		$ 67.07
Liabilities
Fair value measurements tons per year | tons-per-year		1.0		1.0		1.1
Price per ton		$ 103.41		$ 103.41		$ 67.07
Minimum
ASSETS
Fair value inputs, counterparty credit risk	[1]					2.00%
Fair value measurements tons per year | tons-per-year		0.8		0.8		1.0
Price per ton		$ 10.08		$ 10.08		$ 11.24
Liabilities
Fair value measurements tons per year | tons-per-year		0.8		0.8		1.0
Price per ton		$ 10.08		$ 10.08		$ 11.24
Fair Value, Inputs, Level 3
ASSETS
Commodity contract derivatives		3,000,000		3,000,000		1,000,000
Liabilities
Commodity contract derivatives		128,000,000		128,000,000		97,000,000
Private Partnerships
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance		238,000,000	$ 188,000,000	238,000,000	$ 188,000,000	214,000,000	$ 223,000,000	$ 180,000,000	$ 159,000,000
Purchases		11,000,000	7,000,000	21,000,000	23,000,000
Issuances		0	0	0	0
Sales		(5,000,000)	(6,000,000)	(12,000,000)	(7,000,000)
Settlements		0	0	0	0
Net unrealized gains (losses) deferred as regulatory assets and liabilities		9,000,000	7,000,000	15,000,000	13,000,000
Commodity Contract Derivatives
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Balance		(125,000,000)	(146,000,000)	(125,000,000)	(146,000,000)	$ (96,000,000)	$ (149,000,000)	$ (131,000,000)	$ (140,000,000)
Purchases		0	0	0	0
Issuances		0	0	0	0
Sales		0	0	0	0
Settlements		0	0	0	0
Net unrealized gains (losses) deferred as regulatory assets and liabilities		$ 24,000,000	$ (15,000,000)	$ (29,000,000)	$ (6,000,000)
[1] Applies to two contracts.

X

- Definition

The fair value as of the balance sheet date of firm obligations in physical commodity contracts (for example, agricultural products, metals and energy).

+ References

No definition available.

+ Details

Name:	tve_Commoditycontractderivativeliabilitiesfairvaluedisclosure
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

X

- Definition

This item represents the amount of the total realized and unrealized gains or losses for the period which are deferred as regulatory assets and liabilities; the fair value of which assets or liabilities was or is measured on a recurring basis using significant unobservable inputs (Level 3).

+ References

No definition available.

+ Details

Name:	tve_FairValueAssetsOrLiabilitiesMeasuredOnRecurringBasisGainLossDeferredAsRegulatoryAssetsOrLiabilities
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Issues that have taken place during the period in relation to assets or liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

No definition available.

+ Details

Name:	tve_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetOrLiabilityIssues
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Purchases that have taken place during the period in relation to assets or liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

No definition available.

+ Details

Name:	tve_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetOrLiabilityPurchases
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Sales that have taken place during the period in relation to assets or liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

No definition available.

+ Details

Name:	tve_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetOrLiabilitySales
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Settlements that have taken place during the period in relation to assets or liabilities measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

No definition available.

+ Details

Name:	tve_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetOrLiabilitySettlements
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

This element represents an asset or liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

No definition available.

+ Details

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

X

- Definition

The fair value measurement of tons per year used to determine fair value

+ References

No definition available.

+ Details

Name:	tve_FairValueMeasurementsTonsPerYear
Namespace Prefix:	tve_
Data Type:	num:weightItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The number of contracts the range applies to.

+ References

No definition available.

+ Details

Name:	tve_NumberOfContracts
Namespace Prefix:	tve_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The price per ton used for the determination of fair value.

+ References

No definition available.

+ Details

Name:	tve_PricePerTon
Namespace Prefix:	tve_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

X

- References

No definition available.

+ Details

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

X

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4A



-Subparagraph (b)



-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5618551-113959



Reference 2: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 815



-SubTopic 10



-Section 50



-Paragraph 4C



-Subparagraph (a),(c),(d),(e)



-URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624171-113959

+ Details

Name:	us-gaap_DerivativeGainLossOnDerivativeNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Risk that one party to the contract will default expressed as a percentage, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef



-Publisher FASB



-Name Accounting Standards Codification



-Topic 820



-SubTopic 10



-Section 50



-Paragraph 2



-Subparagraph (bbb)



-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsCounterpartyCreditRisk
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The fair value as of the balance sheet date of firm holdings in physical commodity contracts (for example, agricultural products, metals and energy). Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

+ References

No definition available.

+ Details

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

X

- References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	tve_FairValueByClassAxis=us-gaap_PartnershipInterestMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	tve_FairValueByClassAxis=us-gaap_CommodityContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: