Note 6 - Fair Value of Financial Instruments (Details) - Fair Value Information for Financial Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Current assets:
Cash equivalents (including restricted cash accounts)	$ 57,354
Cash equivalents (including restricted cash accounts)	40,015		54,298
Derivatives:
Derivatives at Fair Value	39,474		60,955
Forward Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Derivatives at Fair Value		[1]		[1]
Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Derivatives at Fair Value	2,290	[1]	1,675	[1]
Forward Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Derivatives at Fair Value		[1]		[1]
Forward Contracts [Member]
Derivatives:
Derivatives at Fair Value	2,290	[1]	1,675	[1]
Forward Contracts [Member] | Portion at Other than Fair Value Measurement [Member]
Derivatives:
Derivatives at Carrying Amount	2,290	[1]	1,675	[1]
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Derivatives at Fair Value		[2]		[2]
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Derivatives at Fair Value	(2,490)	[2]	336	[2]
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Derivatives at Fair Value		[2]		[2]
Crude Oil Price Swap [Member]
Derivatives:
Derivatives at Fair Value	(2,490)	[2]	336	[2]
Crude Oil Price Swap [Member] | Portion at Other than Fair Value Measurement [Member]
Derivatives:
Derivatives at Carrying Amount	(2,490)	[2]	336	[2]
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Derivatives at Fair Value		[3]
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Derivatives at Fair Value	(341)	[3]	2,804
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Derivatives at Fair Value		[3]
Natural Gas Price Swap [Member]
Derivatives:
Derivatives at Fair Value	(341)	[3]	2,804
Natural Gas Price Swap [Member] | Portion at Other than Fair Value Measurement [Member]
Derivatives:
Derivatives at Carrying Amount	(341)	[3]	2,804
Put Option [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Derivatives at Fair Value			1,842
Put Option [Member]
Derivatives:
Derivatives at Fair Value			1,842
Put Option [Member] | Portion at Other than Fair Value Measurement [Member]
Derivatives:
Derivatives at Carrying Amount			1,842
Fair Value, Inputs, Level 1 [Member]
Current assets:
Cash equivalents (including restricted cash accounts)	40,015		54,298
Derivatives:
Derivatives at Fair Value	40,015		54,298
Fair Value, Inputs, Level 2 [Member]
Derivatives:
Derivatives at Fair Value	(541)		6,657
Portion at Other than Fair Value Measurement [Member]
Current assets:
Cash equivalents (including restricted cash accounts)	40,015		54,298
Derivatives:
Derivatives at Carrying Amount	$ 39,474		$ 60,955

[1] These amounts relate to derivatives which represent currency forward contracts valued primarily based on observable inputs, including forward and spot prices for currencies, netted against contracted rates and then multiplied against notional amounts, and are included within "prepaid expenses and other" in the consolidated balance sheet with the corresponding gain or loss being recognized within "foreign currency translation and transaction gains (losses)" in the consolidated statement of operations and comprehensive income (loss).

[2] This amount relates to derivatives which represent swap contract on oil prices, valued primarily based on observable inputs, including forward and spot prices for related commodity indices, and are included within "accounts payable and accrued expenses" and "prepaid expenses and other" on December 31, 2013 and 2012, respectively, in the consolidated balance sheets with the corresponding gain or loss being recognized within "electricity revenues" in the consolidated statement of operations and comprehensive income (loss).

[3] This amount relates to derivatives which represent swap contract on natural gas prices, valued primarily based on observable inputs, including forward and spot prices for related commodity indices, and are included within "accounts payable and accrued expenses" and "prepaid expenses and other" on December 31, 2013 and 2012, respectively, in the consolidated balance sheets with the corresponding gain or loss being recognized within "electricity revenue" in the consolidated statement of operations and comprehensive income (loss).