Note 19 - Concentrations - Concentration Risk (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
UNITED KINGDOM
Concentration risk, percentage	15.00%	17.00%	13.00%	17.00%
Sales Revenue, Net [Member] | Power and Electromechanical Segment [Member]
Concentration risk, percentage	79.00%	77.00%	82.00%	78.00%
Sales Revenue, Net [Member] | Energy Segment [Member]
Concentration risk, percentage	21.00%	23.00%	18.00%	22.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration risk, percentage	39.00%	27.00%	39.00%	26.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Power and Electromechanical Segment [Member] | Digi Key Electronics [Member]
Concentration risk, percentage	26.00%	27.00%	26.00%	26.00%
Sales Revenue, Net [Member] | Customer Concentration Risk [Member] | Power and Electromechanical Segment [Member] | Future Electronics [Member]
Concentration risk, percentage	13.00%		13.00%
Sales Revenue, Net [Member] | Geographic Concentration Risk [Member]
Concentration risk, percentage	15.00%	17.00%	13.00%	17.00%
Sales Revenue, Net [Member] | Geographic Concentration Risk [Member] | UNITED KINGDOM
Concentration risk, percentage	15.00%	17.00%	13.00%	17.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration risk, percentage			12.00%		21.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Power and Electromechanical Segment [Member] | Future Electronics [Member]
Concentration risk, percentage			12.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Power and Electromechanical Segment [Member] | GL Industrial Services UK Ltd. [Member]
Concentration risk, percentage					11.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Energy Segment [Member] | Digi Key Electronics [Member]
Concentration risk, percentage					10.00%
Accounts Receivable [Member] | Geographic Concentration Risk [Member]
Concentration risk, percentage			37.00%		39.00%
Accounts Receivable [Member] | Geographic Concentration Risk [Member] | UNITED KINGDOM
Concentration risk, percentage			26.00%		28.00%
Accounts Receivable [Member] | Geographic Concentration Risk [Member] | CANADA
Concentration risk, percentage			11.00%		11.00%