Aquisitions and Dispositions	6 Months Ended
Jun. 30, 2011
Acquisitions and Dispositions [Abstract]
Acquisitions and Dispositions	5. ACQUISITION AND DISPOSITIONS ACQUISITION 2010 Valley Electric Membership Corporation (Utility Operations segment) In October 2010, SWEPCo purchased certain transmission and distribution assets of Valley Electric Membership Corporation (VEMCO) for approximately $102 million and began serving VEMCO's 30,000 customers in Louisiana. DISPOSITIONS 2010 Electric Transmission Texas LLC (ETT) (Utility Operations segment) During the six months ended June 30, 2010, TCC and TNC sold, at cost, $64 million and $71 million, respectively, of transmission facilities to ETT. Intercontinental Exchange, Inc. (ICE) (All Other) In April 2010, we sold our remaining 138,000 shares of ICE and recognized a $16 million gain ($10 million, net of tax). We recorded the gain in Interest and Investment Income on our Condensed Consolidated Statements of Income for the three months ended June 30, 2010.
Southwestern Electric Power Co [Member]
Acquisitions and Dispositions [Abstract]
Acquisitions and Dispositions	5. ACQUISITION 2010 Valley Electric Membership Corporation – Affecting SWEPCo In October 2010, SWEPCo purchased certain transmission and distribution assets of Valley Electric Membership Corporation (VEMCO) for approximately $102 million and began serving VEMCO's 30,000 customers in Louisiana.

Tabular disclosure of all information related to any significant acquisition and disposal. Disclosure may include methodology and assumptions, type of asset, asset classification, useful life, useful purpose, acquisition cost, method of acquisition or disposal, depreciation method, gain (loss) on disposal pretax and net of tax, date of acquisition or disposal and restrictions on amount of proceeds from donated assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 144
-Paragraph 47
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6360339&loc=d3e1361-107760

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