Note 4 - Unconsolidated Investments (Details) (USD $)	6 Months Ended				0 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 Sarulla [Member] Subject to Fixed Interest Rate [Member] Lenders Consortium [Member]	Jun. 30, 2014 Sarulla [Member] Subject to LIBOR based Interest Rate [Member] Lenders Consortium [Member]	Jun. 30, 2014 Sarulla [Member] Subject to Fixed LIBOR Interest Rate [Member] Interest Rate Swap [Member] Lenders Consortium [Member]	Jun. 04, 2014 Sarulla [Member] Interest Rate Swap [Member] London Interbank Offered Rate (LIBOR) [Member] Lenders Consortium [Member]	Jun. 04, 2014 Sarulla [Member] Interest Rate Swap [Member] Lenders Consortium [Member]	Jun. 30, 2014 Sarulla [Member]	Jun. 30, 2014 Sarulla [Member] Interest Rate Swap [Member]	Jun. 30, 2014 Sarulla [Member] Lenders Consortium [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share							12.75%
Expected Power Generating Capacity							330
Contract Effective Date							Apr. 04, 2013
Power Plant Usage Agreement Term							30 years
Number Of Phases Of Construction							3
Power Utilization							110
Senior Notes		$ 100,000,000	$ 1,070,000,000	$ 960,000,000					$ 1,170,000,000
Debt Instrument, Basis Spread on Variable Rate					3.4565%
Proceeds from Issuance of Senior Long-term Debt						50,000,000
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion								32,000,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(4,088,000)							4,100,000
Construction Commenced Date							2016
Period To Start Remaining Phases Of Construction After Commencement Of First Phase							18 months
Supply Commitment, Remaining Minimum Amount Committed							254,000,000
Payments to Acquire Projects							$ 600,000