Note 15 - Concentrations (Details Textual) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, before Allowance for Credit Loss	$ 5.3	$ 5.1
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Two Customers [Member]
Concentration Risk, Percentage	31.00%	27.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | S & B Engineers [Member]
Concentration Risk, Percentage	21.00%	12.00%	11.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Costain Oil, Gas & Process Ltd [Member]
Concentration Risk, Percentage	10.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | National Grid [Member]
Concentration Risk, Percentage		15.00%	26.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Three Customers [Member]
Concentration Risk, Percentage			55.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Scotia Gas Networks plc [Member]
Concentration Risk, Percentage			18.00%
Revenue Benchmark [Member] | Geographic Concentration Risk [Member]
Concentration Risk, Percentage	100.00%	100.00%	100.00%
Revenue Benchmark [Member] | Geographic Concentration Risk [Member] | UNITED KINGDOM
Concentration Risk, Percentage	57.00%	74.00%	77.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Two Customers [Member]
Concentration Risk, Percentage		38.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | S & B Engineers [Member]
Concentration Risk, Percentage	12.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Costain Oil, Gas & Process Ltd [Member]
Concentration Risk, Percentage	14.00%	24.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | National Grid [Member]
Concentration Risk, Percentage		14.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Three Customers [Member]
Concentration Risk, Percentage	50.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Energy Transfer [Member]
Concentration Risk, Percentage	24.00%
Accounts Receivable [Member] | Geographic Concentration Risk [Member] | UNITED KINGDOM
Concentration Risk, Percentage	49.00%	80.00%	79.00%
Cost of Goods and Service Benchmark [Member] | Supplier Concentration Risk [Member]
Concentration Risk, Percentage	0.00%	0.00%	0.00%