Note 8 - Property, Equipment and Construction in Progress (Details) - Property, Equipment and Construction in Progress (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Producing properties (successful efforts method of accounting)	$ 147,071	$ 140,937
Accumulated depletion, depreciation and amortization	(129,107)	(123,319)
Property, equipment and construction in progress, net	165,971us-gaap_PropertyPlantAndEquipmentNet	217,753us-gaap_PropertyPlantAndEquipmentNet
Power Plant [Member]
Property, Plant and Equipment [Line Items]
Construction in Progress	32,801	82,928
Platforms and Wells [Member]
Property, Plant and Equipment [Line Items]
Construction in Progress	30,363	12,505
Pipelines and Processing Facilities [Member]
Property, Plant and Equipment [Line Items]
Construction in Progress	892	846
Other Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Construction in Progress	216	556
Producing Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	40,315	40,209
Barge and Related Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	34,289	53,969
Office Equipment, Leasehold Improvements And Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 9,131	$ 9,122

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

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Oil and Gas properties, gross, carried under the successful effort method.

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