Expected volume of natural gas subject to option to sell back excess gas due to operational constraints.

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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- Definition

The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4H
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624258-113959

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

The estimated net amount of unrealized gains or losses on foreign currency cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

+ Details

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Derivatives - Narrative (Details) BTU in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) BTU	Dec. 31, 2016 USD ($)
Derivative [Line Items]
Collateral already posted, aggregate fair value	$ 92
Maximum potential collateral requirements arising from credit risk related contingent features	$ 11
Southern Company [Member]
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| BTU	10
Georgia Power [Member]
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| BTU	4
Southern Power [Member]
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| BTU	3
Cash flow hedge gain (loss) to be reclassified within twelve months	$ 10
Parent Company And Georgia Power [Member]
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| BTU	1
Parent Company and Southern Power [Member]
Derivative [Line Items]
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months	$ 24
Southern Company Gas [Member]
Derivative [Line Items]
Collateral already posted, aggregate fair value	92	$ 62
Maximum potential collateral requirements arising from credit risk related contingent features	2
Traditional Operating Companies and Southern Power [Member]
Derivative [Line Items]
Maximum potential collateral requirements arising from credit risk related contingent features	9
Derivative Counterparties [Member] \| Registrants [Member]
Derivative [Line Items]
Collateral already posted, aggregate fair value	$ 0