Note 10 - Segment Reporting - Segment Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018		Mar. 31, 2017		Jan. 01, 2018	Dec. 31, 2017
Revenues from external customers	$ 21,966		$ 17,844
Depreciation and amortization(1)	730	[1]	700	[2]
Interest expense	114		116
Profit (loss) from operations	(3,779)		(4,010)
Segment assets	83,925		78,903		$ 86,329	$ 87,909
Other intangible assets, net	15,608		15,867			15,568
Goodwill	17,820		20,217			17,641
Expenditures for long-lived assets (2)	393	[3]	269	[4]
Power and Electromechanical Segment [Member]
Revenues from external customers	17,020		13,662
Depreciation and amortization(1)	364	[1]	381	[2]
Interest expense	53		54
Profit (loss) from operations	9		(534)
Segment assets	45,401		49,414
Other intangible assets, net	8,906		9,082
Goodwill	13,097		13,089			13,092
Expenditures for long-lived assets (2)	320	[3]	204	[4]
Energy Segment [Member]
Revenues from external customers	4,946		4,182
Depreciation and amortization(1)	366	[1]	319	[2]
Interest expense	2
Profit (loss) from operations	(2,524)		(2,264)
Segment assets	29,645		29,180
Other intangible assets, net	6,702		6,785
Goodwill	4,723		7,128			$ 4,549
Expenditures for long-lived assets (2)	73	[3]	65	[4]
Corporate and Other [Member]
Revenues from external customers
Depreciation and amortization(1)		[1]		[2]
Interest expense	59		62
Profit (loss) from operations	(1,264)		(1,212)
Segment assets	8,879		309
Other intangible assets, net
Goodwill
Expenditures for long-lived assets (2)		[3]		[4]

[1] For the Power and Electromechanical segment, for the three months ended March 31, 2018, depreciation and amortization includes $201 thousand classified as cost of revenues in the Condensed Consolidated Statements of Operations.

[2] For the Power and Electromechanical segment, depreciation and amortization totals for the three months ended March 31, 2017, include $148 thousand classified as cost of revenues in the Condensed Consolidated Statements of Operations.

[3] Includes purchases of property, plant and equipment and the investment in other intangible assets.

[4] Includes purchases of property plant and equipment and the investment in other intangible assets.