Note 10 - Segment Reporting (Details Textual) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Number of Operating Segments	6
Concentration Risk, Percentage	100.00%	100.00%
Power and Electromechanical and Energy Segments [Member]
Number of Reportable Segments	2
Power and Electromechanical Segment [Member]
Cost, Depreciation, Amortization and Depletion, Total	$ 201	$ 148
Power and Electromechanical Segment [Member] \| Sales Revenue, Net [Member]
Concentration Risk, Percentage	77.00%	77.00%
Energy Segment [Member] \| Sales Revenue, Net [Member]
Concentration Risk, Percentage		23.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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