Leaseback Obligations	9 Months Ended
Jun. 30, 2012
Leaseback Obligations [Abstract]
Leaseback Obligations	Leaseback Obligations Lease/Leasebacks Prior to 2004, TVA received approximately $945 million in proceeds by entering into leaseback transactions for 24 new peaking combustion turbine units (“CTs”). TVA also received approximately $389 million in proceeds by entering into a leaseback transaction for qualified technological equipment and software (“QTE”) in 2003. Due to TVA's continuing involvement in the operation and maintenance of the leased units and equipment and its control over the distribution of power produced by the combustion turbine facilities during the leaseback term, TVA accounted for the lease proceeds as financing obligations. At June 30, 2012, and September 30, 2011, the outstanding leaseback obligations, related to CTs and QTE, were $827 million and $885 million, respectively. Seven States Power Corporation ("Seven States"), through its subsidiary, Seven States Southaven, LLC ("SSSL"), exercised its option to purchase from TVA an undivided 90 percent interest in a combined cycle combustion turbine facility in Southaven, Mississippi. As part of interim joint-ownership arrangements, Seven States has the right at any time, and for any reason, until the earlier of the date long-term operational and power sales arrangements are in place or April 23, 2013, to require TVA to buy back Seven States's interest in the facility. TVA will buy back Seven States's interest if long-term operational and power sales arrangements for the facility among TVA, Seven States, and SSSL, or alternative arrangements, are not in place by April 23, 2013. TVA's buy-back obligation will terminate if such long-term arrangements are in place by that date. In the event of a buy-back, TVA will re-acquire Seven States's interest in the facility and the related assets. The carrying amount of the Southaven obligation on TVA's consolidated balance sheets was approximately $383 million at June 30, 2012, and $397 million at September 30, 2011. As of June 30, 2012, this obligation was recorded in Current portion of leaseback obligations on the Consolidated Balance Sheets. Bond Ratings Downgrade On August 8, 2011, a credit rating agency lowered the long-term rating of TVA's rated Bonds from AAA to AA+. This downgrade constituted an event of default under the Amended and Restated Credit Agreement between Seven States and its lenders. Upon the occurrence of such an event of default, Seven States's lenders may either impose a higher default interest rate on the loan or exercise an option to require TVA to re-acquire its interest in the Southaven facility and the related assets. On November 1, 2011, Seven States and its lenders, with the consent of TVA, executed an Amendment to the Amended and Restated Credit Agreement. In this amendment, Seven States's lenders agreed to waive this event of default and thus waive the lenders' right to force TVA to re-acquire Seven States's interest in the Southaven facility and the related assets or to force Seven States to pay the default interest rate for this event of default. Also, the amendment ties the interest rate on Seven States's credit facilities to TVA's credit rating. Seven States will pay interest on the loan at either (1) the London Interbank Offer Rate ("LIBOR") plus 62.5 basis points if TVA's corporate credit rating is AAA (or its equivalent) by the nationally recognized credit rating agencies, or (2) LIBOR plus 87.5 basis points if TVA's corporate credit rating is AA+ (or its equivalent) by one or more nationally recognized credit rating agencies. Lease Ratings Downgrade On November 29, 2011, one credit rating agency downgraded its ratings on various long-term leases backed by obligations of TVA from AA+ to AA-, and set the outlook on the ratings to stable. The downgrades include leaseback obligations related to CTs, QTE, and office real estate. According to the rating agency, the downgrade reflects the application of new criteria to the leases, rather than any TVA action, event, or change in business conditions. While the downgrades do not change TVA's obligations under the leases, they may affect the cost to TVA of similar future financings.

Leaseback Obligations

Lease/Leasebacks

Prior to 2004, TVA received approximately $945 million in proceeds by entering into leaseback transactions for 24 new peaking combustion turbine units (“CTs”). TVA also received approximately $389 million in proceeds by entering into a leaseback transaction for qualified technological equipment and software (“QTE”) in 2003. Due to TVA's continuing involvement in the operation and maintenance of the leased units and equipment and its control over the distribution of power produced by the combustion turbine facilities during the leaseback term, TVA accounted for the lease proceeds as financing obligations. At June 30, 2012, and September 30, 2011, the outstanding leaseback obligations, related to CTs and QTE, were $827 million and $885 million, respectively.

Seven States Power Corporation ("Seven States"), through its subsidiary, Seven States Southaven, LLC ("SSSL"), exercised its option to purchase from TVA an undivided 90 percent interest in a combined cycle combustion turbine facility in Southaven, Mississippi. As part of interim joint-ownership arrangements, Seven States has the right at any time, and for any reason, until the earlier of the date long-term operational and power sales arrangements are in place or April 23, 2013, to require TVA to buy back Seven States's interest in the facility. TVA will buy back Seven States's interest if long-term operational and power sales arrangements for the facility among TVA, Seven States, and SSSL, or alternative arrangements, are not in place by April 23, 2013. TVA's buy-back obligation will terminate if such long-term arrangements are in place by that date. In the event of a buy-back, TVA will re-acquire Seven States's interest in the facility and the related assets. The carrying amount of the Southaven obligation on TVA's consolidated balance sheets was approximately $383 million at June 30, 2012, and $397 million at September 30, 2011. As of June 30, 2012, this obligation was recorded in Current portion of leaseback obligations on the Consolidated Balance Sheets.

Bond Ratings Downgrade

On August 8, 2011, a credit rating agency lowered the long-term rating of TVA's rated Bonds from AAA to AA+. This downgrade constituted an event of default under the Amended and Restated Credit Agreement between Seven States and its lenders. Upon the occurrence of such an event of default, Seven States's lenders may either impose a higher default interest rate on the loan or exercise an option to require TVA to re-acquire its interest in the Southaven facility and the related assets. On November 1, 2011, Seven States and its lenders, with the consent of TVA, executed an Amendment to the Amended and Restated Credit Agreement. In this amendment, Seven States's lenders agreed to waive this event of default and thus waive the lenders' right to force TVA to re-acquire Seven States's interest in the Southaven facility and the related assets or to force Seven States to pay the default interest rate for this event of default. Also, the amendment ties the interest rate on Seven States's credit facilities to TVA's credit rating. Seven States will pay interest on the loan at either (1) the London Interbank Offer Rate ("LIBOR") plus 62.5 basis points if TVA's corporate credit rating is AAA (or its equivalent) by the nationally recognized credit rating agencies, or (2) LIBOR plus 87.5 basis points if TVA's corporate credit rating is AA+ (or its equivalent) by one or more nationally recognized credit rating agencies.

Lease Ratings Downgrade

On November 29, 2011, one credit rating agency downgraded its ratings on various long-term leases backed by obligations of TVA from AA+ to AA-, and set the outlook on the ratings to stable. The downgrades include leaseback obligations related to CTs, QTE, and office real estate. According to the rating agency, the downgrade reflects the application of new criteria to the leases, rather than any TVA action, event, or change in business conditions. While the downgrades do not change TVA's obligations under the leases, they may affect the cost to TVA of similar future financings.