Note 7 - Concentrations (Details Textual)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019
Number of Areas in Which Operations are Concentrated			1
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | U.S. Government [Member]
Concentration Risk, Percentage	91.30%	88.40%
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | Three Government Customers [Member]
Concentration Risk, Percentage	73.20%
Number of Major Customers	3
Customer Concentration Risk [Member] | Revenue Benchmark [Member] | One Commercial Customer [Member]
Concentration Risk, Percentage		10.20%
Number of Major Customers		1
Customer Concentration Risk [Member] | Accounts Receivable [Member] | Four Government Customers [Member]
Concentration Risk, Percentage		73.70%
Number of Major Customers		4