Common Stock Fees and Commissions

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- Definition

Number Of Employees Participating in Restricted Stock Unit and Performance Share Units Program

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- Definition

Number Of Employees Participating in Stock Option and Performance Share Units Program

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- Definition

Number of Performance Goals

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- Definition

Share based compensation arrangement by share based payment award number of shares reserved for issuance pursuant to stock based compensation plan.

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- Definition

Share Based Compensation, Shares Vested and Issued Each Year Employee Remains In Service At Each Vest Year, Percentage

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- Definition

Stock issued during period shares company investment plan and employee and director stock plans.

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- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

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The cash inflow from the additional capital contribution to the entity.

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- Definition

Amount of cash inflow from issuance of shares under share-based compensation arrangement. Issuance includes, but is not limited to, exercise of stock options and similar instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
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-Publisher FASB
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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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-Topic 718
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-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

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- Definition

Number of new stock issued during the period.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
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Common Stock and Stock Compensation - Textual Stock Issued, Reserved, Employee (Details) $ / shares in Units, shares in Thousands, $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jan. 31, 2017 USD ($)	Dec. 31, 2016 USD ($) shares	Dec. 31, 2017 USD ($) goal Employee shares	Dec. 31, 2016 USD ($) shares	Dec. 31, 2015 USD ($) shares	Jul. 01, 2016 $ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Performance Goals \| goal			3
Shares vested and issued each year employee remains in service			33.00%
Number of employees participating in restricted stock unit and performance share units program \| Employee			327
Common stock \| $			$ 793.0	$ 3,758.0	$ 256.0
Common stock fees and commissions \| $		$ 1.1
Stock issued employee and director stock plans			14,600
Proceeds from issuance of shares under share-based compensation plans \| $			$ 659.0
Number of shares reserved for issuance to stock-based compensation plan			71,000
Number of employees participating in stock-based compensation plans \| Employee			5,112
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued (in shares)			17,319	76,140	6,571
Treasury
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued (in shares)			0	2,599	2,599
At-The-Market \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued (in shares)		2,700
Common stock \| $		$ 134.0
Southern Company Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining shares available for awards			13,000
ALABAMA POWER CO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested and issued each year employee remains in service			33.00%
Number of employees participating in stock-based compensation plans \| Employee			793
GEORGIA POWER CO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested and issued each year employee remains in service			33.00%
Vesting period of performance share units issued under performance share plan			3 years
Number of employees participating in stock-based compensation plans \| Employee			895
GULF POWER CO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested and issued each year employee remains in service			33.00%
Vesting period of performance share units issued under performance share plan			3 years
Common stock \| $	$ 175.0		$ 175.0	$ 0.0	$ 20.0
Number of employees participating in stock-based compensation plans \| Employee			168
GULF POWER CO \| Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued (in shares)			0		1,000
MISSISSIPPI POWER CO
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of performance share units issued under performance share plan			3 years
Number of employees participating in stock-based compensation plans \| Employee			180
SOUTHERN Co GAS
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested and issued each year employee remains in service			33.00%
Southern Company \| SOUTHERN Co GAS
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Business acquisition share price (in dollars per share) \| $ / shares						$ 66