XML 51 R53.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Asset Retirement Obligations (Details) (USD $) In Millions, unless otherwise specified | 6 Months Ended
--- | ---
Mar. 31, 2015
Asset Retirement Obligations |  |
Asset retirement obligations, period increase (decrease) | $ 54 us-gaap_AssetRetirementObligationPeriodIncreaseDecrease |
Decommissioning study update - ARO nuclear | 5 years |
Accretion expense | 22 us-gaap_AccretionExpense |
Balance at September 30, 2014 | 3,169 us-gaap_AssetRetirementObligation | [1]
Settlements (ash storage areas) | (21)us-gaap_AssetRetirementObligationLiabilitiesSettled | [1]
Accretion (recorded as regulatory asset) | 75 tve_AccretionRecordedAsRegulatoryAsset | [1]
Balance at March 31, 2015 | 3,223 us-gaap_AssetRetirementObligation | [1]
Current portion of ARO | 115 us-gaap_AssetRetirementObligationCurrent |
Nuclear |  |
Asset Retirement Obligations |  |
Balance at September 30, 2014 | 2,052 us-gaap_AssetRetirementObligation / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NuclearMember | [1]
Settlements (ash storage areas) | 0 us-gaap_AssetRetirementObligationLiabilitiesSettled / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NuclearMember | [1]
Accretion (recorded as regulatory asset) | 49 tve_AccretionRecordedAsRegulatoryAsset / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NuclearMember | [1]
Balance at March 31, 2015 | 2,101 us-gaap_AssetRetirementObligation / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NuclearMember | [1]
Non-nuclear |  |
Asset Retirement Obligations |  |
Balance at September 30, 2014 | 1,117 us-gaap_AssetRetirementObligation / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NonNuclearMember | [1]
Settlements (ash storage areas) | (21)us-gaap_AssetRetirementObligationLiabilitiesSettled / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NonNuclearMember | [1]
Accretion (recorded as regulatory asset) | 26 tve_AccretionRecordedAsRegulatoryAsset / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NonNuclearMember | [1]
Balance at March 31, 2015 | $ 1,122 us-gaap_AssetRetirementObligation / tve_ReconciliationOfAssetRetirementObligationLiabilityAxis = tve_NonNuclearMember | [1]
[1] | The current portion of ARO in the amount of $115 million is included in Accounts payable and accrued liabilities at March 31, 2015.

X
- Definition The amount of accretion recorded as a regulatory asset during the period. + References No definition available. + Details
Name: | tve_AccretionRecordedAsRegulatoryAsset
Namespace Prefix: | tve_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The maximum number of years in between ARO-nuclear decommissioning study updates. + References No definition available. + Details
Name: | tve_ARONuclearDecommissioningStudyUpdate
Namespace Prefix: | tve_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | tve_ReconciliationOfAssetRetirementObligationsLineItems
Namespace Prefix: | tve_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 35 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6394232&loc=d3e17558-110866 + Details
Name: | us-gaap_AccretionExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Asset Retirement Obligation -URI http://asc.fasb.org/extlink&oid=6505190 + Details
Name: | us-gaap_AssetRetirementObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesSettled
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Net Increase or Decrease in the asset retirement obligation during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | tve_ReconciliationOfAssetRetirementObligationLiabilityAxis=tve_NonNuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | tve_ReconciliationOfAssetRetirementObligationLiabilityAxis=tve_NuclearMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |