Commitments and Contingencies - Narrative (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended		1 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Jun. 30, 2014	May 31, 2014 300 Megawatts Of Renewable Energy [Member] MW	May 31, 2014 274-Megawatt Natural Gas Facility [Member] MW	May 31, 2014 222-Megawatt Natural Gas Facility [Member] MW	May 31, 2014 15-Megawatt Solar Facility [Member] MW	May 31, 2014 200-Megawatt Solar facility [Member] MW
Public Utilities, General Disclosures [Line Items]
New Generation Capacity				300	274	222	15	200
Amount awarded unpaid rent	$ 1
Amount awarded inverse condemnation and interest	5
Total judgment amount		12
Loss Contingency, Amount of Bond Posted			$ 6