Risk Management Activities and Derivative Transactions Mark-to-Market Values of TVA Derivatives (Details) (USD $)
In Millions, unless otherwise specified

Mar. 31, 2013

Sep. 30, 2012

200 million Sterling currency swap | Other long-term liabilities

Derivatives, Fair Value

Fair value

$ (37)

$ (23)

250 million Sterling currency swap | Other long-term assets

Derivatives, Fair Value

Fair value

150 million Sterling currency swap | Other long-term liabilities

Derivatives, Fair Value

Fair value

(26)

(31)

$1.0 billion notional interest rate swap | Other long-term liabilities

Derivatives, Fair Value

Fair value

(1,101)

(1,247)

$476 million notional interest rate swap | Other long-term liabilities

Derivatives, Fair Value

Fair value

(393)

(458)

$42 million notional interest rate swap | Other long-term liabilities

Derivatives, Fair Value

Fair value

(16)

(18)

Coal Contract Derivatives

Derivatives, Fair Value

Fair value

(148)

(267)

Commodity contract derivatives | Other long-term assets

Derivatives, Fair Value

Fair value

107

Commodity contract derivatives | Other long-term liabilities

Derivatives, Fair Value

Fair value

(52)

(205)

Commodity contract derivatives | Other current assets

Derivatives, Fair Value

Fair value

Commodity contract derivatives | Accounts payable and accrued liabilities

Derivatives, Fair Value

Fair value

(103)

(181)

Margin cash account | Other current assets

Derivatives, Fair Value

Fair value

^[1]

Derivatives Under FTP

Derivatives, Fair Value

Fair value

(161)

^[2]

(229)

^[2]

Derivatives Under FTP | Other long-term assets

Derivatives, Fair Value

Fair value

Derivatives Under FTP | Other long-term liabilities

Derivatives, Fair Value

Fair value

(41)

(60)

Derivatives Under FTP | Other current assets

Derivatives, Fair Value

Fair value

(82)

(104)

Derivatives Under FTP | Accounts payable and accrued liabilities

Derivatives, Fair Value

Fair value

$ (39)

$ (67)

[1]	In accordance with certain credit terms, TVA uses leverage to trade financial instruments under the FTP. Therefore, the margin cash account balance does not represent 100 percent of the net market value of the derivative positions outstanding as shown in the Derivatives Under Financial Trading Program table.
[2]