Acquisitions - Schedule of Construction Projects (Details) - MW	1 Months Ended							7 Months Ended	9 Months Ended
	Dec. 31, 2016	Nov. 30, 2016	Oct. 31, 2016	Aug. 31, 2016	Jul. 31, 2016	Mar. 31, 2016	Feb. 29, 2016	Jul. 31, 2016	Sep. 30, 2016	Mar. 29, 2016	Dec. 31, 2015
Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)					299			299	299
PPA Contract Period								20 years
Noncontrolling interest, ownership percentage by parent										15.00%
Capacity of small power production facility									189		110
Southern Power [Member] | RE Garland and Garland A Holdings, LLC [Member]
Business Acquisition [Line Items]
PPA Contract Period				20 years
Southern Power [Member] | RE Tranquility Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)				20	205	30	22	205
PPA Contract Period					18 years	30 years	20 years
Southern Power [Member] | Series of Business Acquisitions [Member]
Business Acquisition [Line Items]
PPA Contract Period									20 years
Class A Membership Interest [Member] | Southern Power [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Percentage of entitled cash distributions										66.00%
Class A Membership Interest [Member] | Southern Power [Member] | Series of Business Acquisitions [Member]
Business Acquisition [Line Items]
Noncontrolling interest, ownership percentage by parent									100.00%
Percentage of entitled cash distributions									51.00%
Class B Membership Interest [Member] | First Solar [Member] | Desert Stateline Holdings, LLC [Member]
Business Acquisition [Line Items]
Percentage of entitled cash distributions										34.00%
Scenario, Forecast [Member] | Southern Power [Member] | Butler Solar LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)	103
PPA Contract Period	30 years
Scenario, Forecast [Member] | Southern Power [Member] | RE Garland and Garland A Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)			185
Scenario, Forecast [Member] | Southern Power [Member] | RE Garland Holdings, LLC [Member]
Business Acquisition [Line Items]
PPA Contract Period			15 years
Scenario, Forecast [Member] | Southern Power [Member] | RE Roserock Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)		160
PPA Contract Period		20 years
Scenario, Forecast [Member] | Southern Power [Member] | Sandhills [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)			146
PPA Contract Period			25 years