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Energy from Wind-Powered Generating facilities.

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Estimated Future Construction Payments

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Finite-Lived Intangible Assets, Amortization Expense, Year Six and Thereafter

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Finite-Lived Intangible Assets, Amortization Expense, Year Two Through Five

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Initial Distribution Received

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The contracted life output of the plant.

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Percentage Of Entitled Cash Distributions

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Power of solar polycrystalline silicon facility.

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Purchased Power Agreement Intangible

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Reimbursable Transmission Costs Receivable

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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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The amount of property, plant, and equipment recognized as of the acquisition date.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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-Name Accounting Standards Codification

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Carrying value as of the balance sheet date of obligations incurred and payable for the acquisition of merchandise, materials, supplies and services pertaining to construction projects such as a housing development or factory expansion not classified as trade payables.

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-Name Accounting Standards Codification

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-Subparagraph (SX 210.7-03.15(a))

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Amount of amortization expense for assets, excluding financial assets and goodwill, lacking physical substance with a finite life expected to be recognized during the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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-Topic 350

-SubTopic 30

-Section 50

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- Definition

The proportionate share of interest (percent) in a jointly owned utility plant.

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-Topic 980

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-Subparagraph (SAB TOPIC 10.C)

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 10

-Section C

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

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Acquisitions - Schedule of Acquisitions (Details) $ in Millions								9 Months Ended
	Oct. 22, 2015 USD ($) MW	Sep. 04, 2015 USD ($) MW	Aug. 31, 2015 USD ($) MW	Aug. 28, 2015 USD ($) MW	Apr. 30, 2015 USD ($) MW	Apr. 15, 2015 USD ($) MW	Feb. 24, 2015 USD ($) MW	Sep. 30, 2015 USD ($) MW	Dec. 31, 2014 USD ($)
Southern Power [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW								146
PPA Contract Period								25 years
Construction in Progress, Gross								$ 977.0	$ 11.0
Southern Power [Member] \| Class A Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership								100.00%
Southern Power [Member] \| Kay Wind, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Wind (MW) \| MW							299
Southern Power Percentage Ownership							100.00%
PPA Contract Period							20 years
Approx. Purchase Price							$ 492.0
Southern Power [Member] \| Grant Wind, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Wind (MW) \| MW		151
Southern Power Percentage Ownership		100.00%
PPA Contract Period		20 years
Approx. Purchase Price		$ 264.0
Southern Power [Member] \| Lost Hills Blackwell Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW						35
Southern Power Percentage Ownership						51.00%
PPA Contract Period						29 years
Approx. Purchase Price						$ 74.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment								$ 98.0
Reimbursable Transmission Costs Receivable								9.0
Southern Power [Member] \| Lost Hills Blackwell Holdings, LLC [Member] \| Class A Membership Interest [Member]
Business Acquisition [Line Items]
Percentage Of Entitled Cash Distributions						51.00%
Southern Power [Member] \| NS Solar Holdings, LLC (North Star) [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW					61
Southern Power Percentage Ownership					51.00%
PPA Contract Period					20 years
Approx. Purchase Price					$ 211.0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment								266.0
Reimbursable Transmission Costs Receivable								21.0
Purchased Power Agreement Intangible								24.0
Southern Power [Member] \| RE Tranquility Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW				204
Southern Power Percentage Ownership				51.00%
PPA Contract Period				18 years
Approx. Purchase Price				$ 100.0
Reimbursable Transmission Costs Receivable				24.0
Construction in Progress, Gross				170.0
Construction Payable				37.0
Estimated Future Construction Payments								215.0
Southern Power [Member] \| Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW			300
Southern Power Percentage Ownership			51.00%
PPA Contract Period			20 years
Approx. Purchase Price			$ 439.0
Purchased Power Agreement Intangible			249.0
Construction in Progress, Gross			413.0
Southern Power [Member] \| Subsequent Event [Member] \| GASNA 31P, LLC (Morelos) [Member]
Business Acquisition [Line Items]
Approx. Nameplate Capacity, Solar (MW) \| MW	15
Southern Power Percentage Ownership	90.00%
PPA Contract Period	20 years
Approx. Purchase Price	$ 45.0
Southern Power [Member] \| Scenario, Plan [Member] \| Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months								6.2
Finite-Lived Intangible Assets, Amortization Expense, Year Two Through Five								12.5
Finite-Lived Intangible Assets, Amortization Expense, Year Six and Thereafter								$ 192.8
Southern Power [Member] \| Turner Renewable Energy [Member] \| Subsequent Event [Member]
Business Acquisition [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	10.00%
First Solar [Member] \| Class B Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership								100.00%
First Solar [Member] \| Lost Hills Blackwell Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Purchase Price						$ 33.0
First Solar [Member] \| Lost Hills Blackwell Holdings, LLC [Member] \| Class B Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership						100.00%
Percentage Of Entitled Cash Distributions						49.00%
First Solar [Member] \| NS Solar Holdings, LLC (North Star) [Member]
Business Acquisition [Line Items]
Approx. Purchase Price			$ 100.0
First Solar [Member] \| NS Solar Holdings, LLC (North Star) [Member] \| Class B Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership			100.00%
First Solar [Member] \| Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. Purchase Price			$ 223.0
First Solar [Member] \| Desert Stateline Holdings, LLC [Member] \| Class B Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership			100.00%
Recurrent Energy [Member] \| RE Tranquility Holdings, LLC [Member]
Business Acquisition [Line Items]
Contribution of Assets				157.0
Initial Distribution Received				$ 100.0
Estimated Future Construction Payments								$ 106.0
Recurrent Energy [Member] \| RE Tranquility Holdings, LLC [Member] \| Class B Membership Interest [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership				100.00%
Southern Power and First Solar [Member] \| Minimum [Member] \| Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								827.0
Southern Power and First Solar [Member] \| Maximum [Member] \| Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Estimated Future Construction Payments								$ 844.0
SRE and Turner Renewable Energy [Member] \| Subsequent Event [Member] \| GASNA 31P, LLC (Morelos) [Member]
Business Acquisition [Line Items]
Southern Power Percentage Ownership	90.00%
Southern Power and Turner Renewable Energy [Member] \| Subsequent Event [Member] \| GASNA 31P, LLC (Morelos) [Member]
Business Acquisition [Line Items]
Approx. Purchase Price	$ 50.0