XML 172 R118.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Commitments and Contingencies Commitments and Contingencies - Purchase Obligations (Details) $ in Millions | 12 Months Ended
--- | ---
Sep. 30, 2016 USD ($) Megawatts Suppliers | Sep. 30, 2015 USD ($) | Sep. 30, 2014 USD ($)
Obligations |  |  |  |
Megawatts provided under power purchase obligations | Megawatts |  | 2,227 |  |
Remaining terms of the agreements, high end of range |  | 16 years |  |
Megawatts provided under transmission obligations | Megawatts |  | 1,450 |  |
Power purchased under agreement |  | $ 261 | $ 262 | $ 264
Maximum term length for the purchase and transportation of coal |  | 4 years |  |
Maximum term length for the purchase, storage, and transportation of natural gas |  | 20 years |  |
Maximum term for purchase of enriched uranium and fabrication of nuclear fuel assemblies |  | 14 years |  |
Fuel purchased under agreement |  | $ 1,500 | 973 | 718
Other purchased under agreement |  | 174 | 93 | $ 91
CT and QTE outstanding leaseback obligation |  | $ 467 | $ 616 |
Purchase Agreements Required by Federal Law |  |  |  |
Obligations |  |  |  |
Megawatts provided under power purchase obligations | Megawatts |  | 259 |  |
Number of suppliers | Suppliers |  | 25 |  |
Purchase Obligations - Coal |  |  |  |
Obligations |  |  |  |
Long-term purchase commitment |  | $ 900 |  |
Purchase Obligations - Natural Gas |  |  |  |
Obligations |  |  |  |
Long-term purchase commitment |  | 1,300 |  |
Purchase Obligations - Fuel |  |  |  |
Obligations |  |  |  |
Long-term purchase commitment | [1] | 4,455 |  |
Purchase Obligations - Nuclear Fuel |  |  |  |
Obligations |  |  |  |
Long-term purchase commitment |  | 2,300 |  |
Purchase Obligations - Other |  |  |  |
Obligations |  |  |  |
Long-term purchase commitment | [2] | $ 896 |  |
[1] | (4) Includes commitments to purchase nuclear fuel, coal, and natural gas, as well as related transportation and storage services.
[2] | (5) Primarily includes long-term service contracts, contracts that contain minimum purchase levels for the purchase of limestone along with related storage and transportation, and contractual obligations related to load control programs.

X
- Definition The outstanding leaseback obligations related to combustion turbine units and qualified technological equipment and software. + References No definition available. + Details
Name: | tve_CtAndQteOutstandingLeasebackObligation
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The expense for fuel purchased under contractual purchase obligations + References No definition available. + Details
Name: | tve_Fuelpurchasedunderagreement
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The maximum term for purchase of enriched uranium and fabrication of nuclear fuel assemblies. + References No definition available. + Details
Name: | tve_Maximumtermforpurchaseofenricheduraniumandfabricationofnuclearfuelassemblies
Namespace Prefix: | tve_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum term length for the purchase and transportation of coal + References No definition available. + Details
Name: | tve_Maximumtermlengthforthepurchaseandtransportationofcoal
Namespace Prefix: | tve_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Maximum term length for the purchase, storage, and transportation of natural gas + References No definition available. + Details
Name: | tve_Maximumtermlengthforthepurchasestorageandtransportationofnaturalgas
Namespace Prefix: | tve_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of megawatts provided under the power purchase obligations. + References No definition available. + Details
Name: | tve_MegawattsProvidedUnderPowerPurchaseObligations
Namespace Prefix: | tve_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Megawatts provided under transmission obligations + References No definition available. + Details
Name: | tve_Megawattsprovidedundertransmissionobligations
Namespace Prefix: | tve_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of suppliers. + References No definition available. + Details
Name: | tve_NumberOfSuppliers
Namespace Prefix: | tve_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition The expense for other contracts purchased under contractual purchase obligations + References No definition available. + Details
Name: | tve_Otherpurchasedunderagreement
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The expense for power purchased under contractual power purchase obligations. + References No definition available. + Details
Name: | tve_PowerPurchasedUnderAgreement
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The high end of the range of remaining terms of the agreements. + References No definition available. + Details
Name: | tve_Remainingtermsoftheagreementshighendofrange
Namespace Prefix: | tve_
Data Type: | us-types:durationStringItemType
Balance Type: | na
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_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier. + References No definition available. + Details
Name: | us-gaap_PurchaseObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=tve_PurchaseAgreementsRequiredByFederalLawMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=tve_PurchaseObligationsCoalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_NaturalGasReservesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=tve_PurchaseObligationsFuelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=tve_PurchaseObligationsNuclearFuelMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=tve_PurchaseObligationsOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |