Derivatives.

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- Definition

Maximum expected volume of natural gas subject to such feature.

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- Definition

Maximum potential collateral requirements arising the from credit-risk-related contingent features.

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- Definition

The amount as of the balance sheet date of the fair value of derivative liabilities that in accordance with the entity's accounting policy was not offset against the right to reclaim cash collateral under a master netting arrangement.

+ References

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FIN39-1

-Paragraph 10B

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 815

-SubTopic 10

-Section 50

-Paragraph 8

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=d3e41678-113959

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- Definition

Amount of gain (loss) from the increase (decrease) in fair value of foreign currency derivatives and nonderivative instruments designated as fair value hedging instruments which were recognized in earnings, net of offsets by the gain (loss) on the hedged item to the extent that the fair value hedge was determined to be effective.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 45

-Subparagraph a(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5618551-113959

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959

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- Definition

Amount of unrealized gain (loss) related to the fair value of interest rate derivatives designated as fair value hedging instruments. Recognized in earnings and offsets the gain (loss) on the hedged item to the extent that the fair value hedge is determined to be effective.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5618551-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5624171-113959

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Derivatives (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Million_British_Thermal_Unit	Sep. 30, 2010
Fair value of derivative liabilities with contingent features
Derivative liabilities	$ 32		$ 32
Derivatives (Textual) [Abstract]
Maximum expected volume of natural gas subject to such a feature (million mmBtu)			2,950,000
Pre-tax gains (losses) from foreign currency derivatives designated as fair value hedging instruments	(3)	5	(2)	5
Pre-tax gains from interest rate derivatives designated as fair value hedging instruments	5	9	7	17
Maximum potential collateral requirements arising the from credit-risk-related contingent features	32		32
Alabama Power [Member]
Fair value of derivative liabilities with contingent features
Derivative liabilities	7		7
Derivatives (Textual) [Abstract]
Maximum potential collateral requirements arising the from credit-risk-related contingent features	32		32
Georgia Power [Member]
Fair value of derivative liabilities with contingent features
Derivative liabilities	16		16
Derivatives (Textual) [Abstract]
Maximum expected volume of natural gas subject to such a feature (million mmBtu)			2,690,000
Maximum potential collateral requirements arising the from credit-risk-related contingent features	32		32
Gulf Power [Member]
Fair value of derivative liabilities with contingent features
Derivative liabilities	2		2
Derivatives (Textual) [Abstract]
Maximum potential collateral requirements arising the from credit-risk-related contingent features	32		32
Mississippi Power [Member]
Fair value of derivative liabilities with contingent features
Derivative liabilities	5		5
Derivatives (Textual) [Abstract]
Pre-tax gains (losses) from foreign currency derivatives designated as fair value hedging instruments	(3)	5	(2)	5
Maximum potential collateral requirements arising the from credit-risk-related contingent features	32		32
Southern Power [Member]
Fair value of derivative liabilities with contingent features
Derivative liabilities	2		2
Derivatives (Textual) [Abstract]
Maximum potential collateral requirements arising the from credit-risk-related contingent features	$ 32		$ 32