Acquisitions	9 Months Ended
Sep. 30, 2013
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS Adobe Solar, LLC On August 27, 2013, Southern Power and TRE, through Southern Turner Renewable Energy, LLC (STR), a jointly-owned subsidiary owned 90% by Southern Power, entered into a purchase agreement with Sun Edison, LLC, the developer of the project, which provides for the acquisition of all of the outstanding membership interests of Adobe Solar, LLC (Adobe) by STR. Adobe is constructing an approximately 20-MW solar generating facility in Kern County, California. The solar facility is expected to begin commercial operation in spring 2014. The output of the plant is contracted under a 20-year PPA with Southern California Edison Company, which is expected to begin in spring 2014. The acquisition is in accordance with Southern Power's overall growth strategy. Southern Power's acquisition of Adobe is expected to occur in spring 2014 and the purchase price is expected to be approximately $100 million. The completion of the acquisition is subject to Sun Edison, LLC achieving certain construction and project milestones by certain dates and various customary conditions to closing. The ultimate outcome of this matter cannot be determined at this time. Campo Verde Solar, LLC On April 23, 2013, Southern Power and TRE, through STR, acquired all of the outstanding membership interests of Campo Verde Solar, LLC (Campo Verde) from First Solar, Inc., the developer of the project. Campo Verde constructed an approximately 139-MW solar photovoltaic facility in Southern California. Commercial operation of the solar facility was declared by Campo Verde on October 25, 2013. The output of the plant is contracted under a 20-year PPA with San Diego Gas & Electric Company, a subsidiary of Sempra Energy, which began on the commercial operation date. The acquisition is in accordance with Southern Power's overall growth strategy. Southern Power's acquisition of Campo Verde included cash consideration of $136.6 million, of which $111.6 million was paid at closing and $25.0 million will be paid upon achievement of certain milestones. The preliminary asset allocation is under evaluation by management; therefore, the allocation of the purchase price to individual assets has not been finalized. Under an engineering, procurement, and construction agreement (Construction Agreement), an additional $328.7 million has been paid to a subsidiary of First Solar, Inc. (Construction Contractor) for the construction of the solar facility. In the event certain unforeseeable conditions occur at the project site, the Construction Contractor may terminate the Construction Agreement, and in the event the Construction Contractor does not achieve certain construction or project development milestones by certain dates, STR may terminate the Construction Agreement. In each case, a subsidiary of First Solar will be required to make a termination payment to STR equal to STR's investment in Campo Verde (net of any tax or other benefits received by STR) and STR will be required to transfer its ownership in Campo Verde to the subsidiary of First Solar (Termination Payment and Transfer). In addition, under the acquisition agreement, a subsidiary of First Solar may require the Termination Payment and Transfer to occur in the event costs relating to certain contingencies exceed a certain threshold until such time that the contingencies are satisfactorily resolved under the terms of the acquisition agreement, and STR may require the Termination Payment and Transfer to occur in the event certain contingencies are not satisfactorily resolved. The ultimate outcome of this matter cannot be determined at this time; however, STR believes the likelihood of a Termination Payment and Transfer to be remote.

Acquisitions

9 Months Ended

Sep. 30, 2013

Adobe Solar, LLC

On August 27, 2013, Southern Power and TRE, through Southern Turner Renewable Energy, LLC (STR), a jointly-owned subsidiary owned 90% by Southern Power, entered into a purchase agreement with Sun Edison, LLC, the developer of the project, which provides for the acquisition of all of the outstanding membership interests of Adobe Solar, LLC (Adobe) by STR. Adobe is constructing an approximately 20-MW solar generating facility in Kern County, California. The solar facility is expected to begin commercial operation in spring 2014. The output of the plant is contracted under a 20-year PPA with Southern California Edison Company, which is expected to begin in spring 2014. The acquisition is in accordance with Southern Power's overall growth strategy.

Southern Power's acquisition of Adobe is expected to occur in spring 2014 and the purchase price is expected to be approximately $100 million.

The completion of the acquisition is subject to Sun Edison, LLC achieving certain construction and project milestones by certain dates and various customary conditions to closing. The ultimate outcome of this matter cannot be determined at this time.

Campo Verde Solar, LLC

On April 23, 2013, Southern Power and TRE, through STR, acquired all of the outstanding membership interests of Campo Verde Solar, LLC (Campo Verde) from First Solar, Inc., the developer of the project. Campo Verde constructed an approximately 139-MW solar photovoltaic facility in Southern California. Commercial operation of the solar facility was declared by Campo Verde on October 25, 2013. The output of the plant is contracted under a 20-year PPA with San Diego Gas & Electric Company, a subsidiary of Sempra Energy, which began on the commercial operation date. The acquisition is in accordance with Southern Power's overall growth strategy.

Southern Power's acquisition of Campo Verde included cash consideration of $136.6 million, of which $111.6 million was paid at closing and $25.0 million will be paid upon achievement of certain milestones. The preliminary asset allocation is under evaluation by management; therefore, the allocation of the purchase price to individual assets has not been finalized. Under an engineering, procurement, and construction agreement (Construction Agreement), an additional $328.7 million has been paid to a subsidiary of First Solar, Inc. (Construction Contractor) for the construction of the solar facility.

In the event certain unforeseeable conditions occur at the project site, the Construction Contractor may terminate the Construction Agreement, and in the event the Construction Contractor does not achieve certain construction or project development milestones by certain dates, STR may terminate the Construction Agreement. In each case, a subsidiary of First Solar will be required to make a termination payment to STR equal to STR's investment in Campo Verde (net of any tax or other benefits received by STR) and STR will be required to transfer its ownership in Campo Verde to the subsidiary of First Solar (Termination Payment and Transfer). In addition, under the acquisition agreement, a subsidiary of First Solar may require the Termination Payment and Transfer to occur in the event costs relating to certain contingencies exceed a certain threshold until such time that the contingencies are satisfactorily resolved under the terms of the acquisition agreement, and STR may require the Termination Payment and Transfer to occur in the event certain contingencies are not satisfactorily resolved. The ultimate outcome of this matter cannot be determined at this time; however, STR believes the likelihood of a Termination Payment and Transfer to be remote.