Acquisitions - Schedule of Construction Projects (Details) - Southern Power [Member] - MW		1 Months Ended		3 Months Ended
	Jan. 06, 2017	Apr. 30, 2017	Mar. 31, 2017	Jun. 30, 2019
Bethel [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)	276
Noncontrolling interest, ownership percentage by parent	100.00%
PPA Contract Period	12 years
East Pecos [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)			120
PPA Contract Period			15 years
Subsequent Event [Member] | Lamesa [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)		102
PPA Contract Period		15 years
Scenario, Forecast [Member] | RE Roserock Holdings, LLC [Member]
Business Acquisition [Line Items]
Approx. nameplate capacity, solar (MW)				345
PPA Contract Period				20 years