Note 13 - Significant Customers (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable | Customer A
Concentration Risk, Percentage	10.00%
Costs And Estimated Earnings In Excess Of Billings | Customer A
Concentration Risk, Percentage		18.00%
Costs And Estimated Earnings In Excess Of Billings | Customer F
Concentration Risk, Percentage	30.00%
Costs And Estimated Earnings In Excess Of Billings | Customer C
Concentration Risk, Percentage		19.00%
Costs And Estimated Earnings In Excess Of Billings | Customer D
Concentration Risk, Percentage		29.00%
Costs And Estimated Earnings In Excess Of Billings | Customer E
Concentration Risk, Percentage		48.00%
Sales Revenue, Net | Customer F
Concentration Risk, Percentage	11.00%
Sales Revenue, Net | Customer E
Concentration Risk, Percentage		23.00%