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Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

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Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of price risk derivatives not designated as hedging instruments.

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Note 6 - Fair Value of Financial Instruments (Details) (USD $)	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 06, 2014 MMBTU	Oct. 16, 2013 MMBTU	Sep. 03, 2013 MMBTU
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Gain (Loss) on Price Risk Derivative Instruments Not Designated as Hedging Instruments	$ 5,700,000	$ (5,000,000)
Asset Impairment Charges			236,377,000us-gaap_AssetImpairmentCharges
Design Capacity [Member] \| North Brawley Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Capacity of Plant (in Megawatts)	50
Target Level [Member] \| North Brawley Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Capacity of Plant (in Megawatts)	27
NGI Swap Contract [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Derivative, Nonmonetary Notional Amount, Energy Measure (in Millions of British Thermal Units)				2,200,000	4,200,000	4,400,000
Underlying, Derivative Energy Measure (in Dollars per Million British Thermal Units)				4.95	4.103	4.035
New York Harbor ULSD Swap Contract [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Underlying, Derivative Energy Measure (in Dollars per Million British Thermal Units)					125.15
Derivative, Nonmonetary Notional Amount, Volume (in Barrels (of Oil))					275,000
Fluctuation in Energy Rate (in Megawatt-hours)					25
Minimum [Member] \| North Brawley Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Capacity of Plant (in Megawatts)	20
Maximum [Member] \| North Brawley Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Capacity of Plant (in Megawatts)	33
North Brawley Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Assets, Fair Value Disclosure	32,000,000
Asset Impairment Charges	229,100,000
Fair Value Inputs, Discount Rate	8.00%
OREG 4 Power Plant [Member]
Note 6 - Fair Value of Financial Instruments (Details) [Line Items]
Assets, Fair Value Disclosure	3,600,000
Asset Impairment Charges	$ 7,300,000
Fair Value Inputs, Discount Rate	8.00%