Other Long-Term Assets Other Long-Term Assets (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Other Long-Term Assets
EnergyRight® receivables	$ 117	$ 115
Unamortized debt Issue cost of power bonds	75	70
Loans and other long-term receivables, net	73	76
Coal contract derivative assets	1	107
Prepaid capacity payments	62	59
Currency swap asset	28	21
Other	89	61
Total other long-term assets	445	509
Energy Right Program
Other Long-Term Assets
Number of days in default	180 days
Energy Right loans receivable, net of discount	150	150
Energy Right Program
Other Long-Term Assets
Number of days in default	180 days
Energy Right Solutions program obligation	$ 186	$ 185

The number of days in default that are determined to be uncollectible.

No definition available.

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- Definition

Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet or in the other-long term assets footnote. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

+ References

No definition available.

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- Definition

Carrying amount as of the balance sheet date of the asset arising from commodity contracts such as futures contracts tied to the movement of a particular commodity, which are expected to be converted into cash or otherwise disposed of after a year or beyond the normal operating cycle, if longer.

+ References

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- Definition

Fair value as of the balance sheet date of foreign currency derivative assets, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized as assets on the balance sheet.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

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- Definition

The current carrying amount of the liability for the freestanding or embedded guarantor's obligations under the guarantee or each group of similar guarantees.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 460

-SubTopic 10

-Section 50

-Paragraph 4

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6851643&loc=d3e12069-110248

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- Definition

Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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- Definition

The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle) and amount due to the Entity from outside sources, including trade accounts receivable, notes and loans receivable, as well as any other types of receivables, net of allowances established for the purpose of reducing such investments and receivables to an amount that approximates their net realizable value.

+ References

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- Definition

The noncurrent portion of the receivable other than from customers, that is amounts expected to be collected after one year or the normal operating cycle, if longer.

+ References

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Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer).

+ References

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- Definition

Carrying amount as of the balance sheet date of amounts paid in advance which will be charged against earnings in periods after one year or beyond the operating cycle, if longer.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section 45

-Paragraph 4

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

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- Definition

The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

+ References

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