Note 10 - Segment Reporting (Details Textual) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020 USD ($)		Jun. 30, 2019 USD ($)		Jun. 30, 2020 USD ($)		Jun. 30, 2019 USD ($)
Number of Operating Segments					5
Number of Reportable Segments					3
Depreciation, Depletion and Amortization, Total	$ 1,549	[1]	$ 625	[2]	$ 2,035	[3]	$ 1,369
Energy Segment [Member] | Cost of Sales [Member]
Depreciation, Depletion and Amortization, Total	125				204
Corporate and Other [Member] | Power and Electromechanical Business [Member] | Discontinued Operations, Held-for-sale [Member]
Disposal Group, Including Discontinued Operation, Intangible Assets	$ 400		8,300		$ 400		8,300
Disposal Group, Including Discontinued Operation, Goodwill			$ 13,100				$ 13,100

[1] For the Electric Power and Solar Infrastructure segment, depreciation and amortization includes $125 thousand, which was included in cost of revenues in the Condensed Consolidated Statements of Operations.

[2] The Other category included depreciation and amortization of discontinued operations.

[3] For the Electric Power and Solar Infrastructure segment, depreciation and amortization includes $204 thousand, which was included in cost of revenues in the Condensed Consolidated Statements of Operations.