Note 4 - Unconsolidated Investments (Details) (USD $)	3 Months Ended		9 Months Ended					0 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014 Sarulla [Member] Subject to Fixed Interest Rate [Member] Lenders Consortium [Member]	Sep. 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]	Sep. 30, 2014 Sarulla [Member]	Sep. 30, 2014 Sarulla [Member]	Sep. 30, 2014 Sarulla [Member] Interest Rate Swap [Member]	Sep. 30, 2014 Sarulla [Member] Lenders Consortium [Member]
Note 4 - Unconsolidated Investments (Details) [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share										12.75%	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												40,500,000
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(933,000)		(933,000)									5,200,000
Period To Start Remaining Phases Of Construction After Commencement Of First Phase											18 months
Supply Commitment, Remaining Minimum Amount Committed										254,000,000	254,000,000
Sales Revenue, Goods, Net	37,736,000	41,755,000	121,266,000	157,329,000						13,800,000	13,800,000
Payments to Acquire Projects											$ 600,000