Acquisitions (Details) (Southern Power [Member], USD $) In Millions, unless otherwise specified	0 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended
	Aug. 27, 2013 Adobe Solar LLC [Member]	Sep. 30, 2013 Adobe Solar LLC [Member] MW	Apr. 23, 2013 Campo Verde Solar LLC [Member]	Sep. 30, 2013 Campo Verde Solar LLC [Member] MW
Business Acquisition [Line Items]
Noncontrolling Interest, Ownership Percentage by Parent		90.00%
Acquisitions (Textual) [Abstract]
Power of solar polycrystalline silicon facility		20		139
Beginning year of output of constructed plant		2014		2013
Life Output Of Plant		20 years		20 years
Cash Consideration for acquisition of the interests in Apex	$ 100.0		$ 136.6
Business Acquisition Cost Paid At Closing			111.6
Business Acquisition Cost Paid Upon Achievement Of Milestones			25.0
Cash Consideration will be paid under MIPA			$ 328.7