Note 5 - Fair Value of Financial Instruments (Details) - Financial Assets and Liabilities at Fair Value (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014		Dec. 31, 2013
Current assets:
Cost or Amortized Cost	$ 42,451		$ 57,354
Fair Value	116,118		40,015
Current liabilities:
Fair Value	115,571		39,474
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Fair Value		[1]
Current liabilities:
Fair Value				[1]
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Fair Value	1,134	[1]
Current liabilities:
Fair Value			(2,490)	[1]
Crude Oil Price Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Fair Value		[1]
Current liabilities:
Fair Value				[1]
Crude Oil Price Swap [Member]
Derivatives:
Fair Value	1,134	[1]
Current liabilities:
Fair Value			(2,490)	[1]
Crude Oil Price Swap [Member] | Reported Value Measurement [Member]
Derivatives:
Cost or Amortized Cost	1,134	[1]
Current liabilities:
Cost or Amortized Cost			(2,490)	[1]
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Fair Value		[2]
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Fair Value	502	[2]
Natural Gas Price Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Fair Value		[2]
Natural Gas Price Swap [Member]
Derivatives:
Fair Value	502	[2]
Natural Gas Price Swap [Member] | Reported Value Measurement [Member]
Derivatives:
Cost or Amortized Cost	502	[2]
Forward Contracts [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives:
Fair Value				[3]
Current liabilities:
Fair Value		[3]
Forward Contracts [Member] | Fair Value, Inputs, Level 2 [Member]
Derivatives:
Fair Value			2,290	[3]
Current liabilities:
Fair Value	(2,183)	[3]
Forward Contracts [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives:
Fair Value				[3]
Current liabilities:
Fair Value		[3]
Forward Contracts [Member]
Derivatives:
Fair Value			2,290	[3]
Current liabilities:
Fair Value	(2,183)	[3]
Forward Contracts [Member] | Reported Value Measurement [Member]
Derivatives:
Cost or Amortized Cost			2,290	[3]
Current liabilities:
Cost or Amortized Cost	(2,183)	[3]
Fair Value, Inputs, Level 1 [Member] | Natural Gas Price Swap [Member]
Current liabilities:
Fair Value				[2]
Fair Value, Inputs, Level 1 [Member]
Current assets:
Fair Value	116,118		40,015
Current liabilities:
Fair Value	116,118		40,015
Fair Value, Inputs, Level 2 [Member] | Natural Gas Price Swap [Member]
Current liabilities:
Fair Value			(341)	[2]
Fair Value, Inputs, Level 2 [Member]
Current liabilities:
Fair Value	(547)		(541)
Fair Value, Inputs, Level 3 [Member] | Natural Gas Price Swap [Member]
Current liabilities:
Fair Value				[2]
Natural Gas Price Swap [Member]
Current liabilities:
Fair Value			(341)	[2]
Natural Gas Price Swap [Member] | Reported Value Measurement [Member]
Current liabilities:
Cost or Amortized Cost			(341)	[2]
Reported Value Measurement [Member]
Current assets:
Cost or Amortized Cost	116,118		40,015
Current liabilities:
Cost or Amortized Cost	$ 115,571		$ 39,474

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

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

[3] This amount relates 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 notational amounts, and are included within "prepaid expenses and other" in the condensed consolidated balance sheet with the corresponding gain or loss being recognized within "foreign currency translation and transaction gains (losses)" in the condensed consolidated statement of operations andcomprehensive income (loss).