Note 13 - Leases (Details Textual)
 3 Months Ended
Mar. 31, 2020
USD ($)
ft²
Mar. 31, 2019
USD ($)
Dec. 31, 2019
USD ($)
Aug. 08, 2019
USD ($)
Aug. 07, 2019
USD ($)
Jan. 01, 2019
USD ($)
Operating Lease, Weighted Average Discount Rate, Percent 6.50%          
Finance Lease, Weighted Average Discount Rate, Percent 8.10%          
Operating Lease, Weighted Average Remaining Lease Term (Year) 1 year 182 days          
Finance Lease, Weighted Average Remaining Lease Term (Year) 328 days          
Operating Lease, Right-of-Use Asset $ 892,000   $ 1,040,000     $ 1,300,000
Operating Lease, Liability, Total 1,158,000         $ 1,800,000
Lease Cost, Operating Leases 229,000          
Operating Lease, Cost 170,000          
Short-term Lease, Cost 59,000          
Variable Lease, Cost 0          
Operating Lease, Payments $ 217,000          
Operating Leases, Rent Expense, Net, Total   $ 142,000        
SAVSU [Member]            
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Right-of-use Asset       $ 233,000 $ 233,000  
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Liability       $ 232,000    
Bothell, Washington Headquarters [Member]            
Area of Real Estate Property (Square Foot) | ft² 32,106          
Lessee, Operating Lease, Renewal Term (Year) 5 years          
Monthly Base Rent Expense $ 63,000          
Menlo Park, California Location [Member]            
Area of Real Estate Property (Square Foot) | ft² 1,250          
Monthly Base Rent Expense $ 5,000          
Albuquerque, New Mexico Location [Member]            
Area of Real Estate Property (Square Foot) | ft² 9,932          
Monthly Base Rent Expense $ 9,000          
Detroit, Michigan Location [Member]            
Area of Real Estate Property (Square Foot) | ft² 106,998          
Lessee, Operating Lease, Renewal Term (Year) 5 years          
Monthly Base Rent Expense $ 15,000