Commitments, Contingencies and Uncertainties (Power Purchase and Sale Agreement) (Details)	12 Months Ended
	Dec. 31, 2019 MW
Freeport Agreement 3 - 25 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	25
Long-term Purchase Commitment, Time Period	13 years 1 month
Long-Term Sale Commitment, Time Period	13 years 1 month
Long-Term Sale Commitment, Maximum Quantity	25
Freeport Agreement 2 - 100 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	100
Long-term Purchase Commitment, Time Period	15 years 7 months
Long-Term Sale Commitment, Time Period	15 years 7 months
Long-Term Sale Commitment, Maximum Quantity	100
Freeport Agreement 1 - 125 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	125
Long-term Purchase Commitment, Time Period	3 years 1 month 19 days
Long-Term Sale Commitment, Time Period	3 years 1 month 19 days
Long-Term Sale Commitment, Maximum Quantity	125
Hatch Solar Energy Center I
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	5
Long-term Purchase Commitment, Time Period	25 years 1 month
Solar Roadrunner
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	20
Long-term Purchase Commitment, Time Period	20 years 1 month
Sun Edison 1
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	10
Long-term Purchase Commitment, Time Period	25 years 1 month
Sun Edison 2
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	12
Long-term Purchase Commitment, Time Period	25 years 1 month
Sun Edison 1 and Sun Edison 2
Long-term Purchase Commitment [Line Items]
Solar Photovoltaic Projects, Number of Units	2
Macho Springs Solar
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	50
Long-term Purchase Commitment, Time Period	20 years 1 month
Plant Capacity	50
Newman Solar
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment, Maximum Quantity	10
Long-term Purchase Commitment, Time Period	30 years 1 month