Note 6 - Leases (Details Textual)	12 Months Ended
	Dec. 31, 2019 USD ($) ft²	Dec. 31, 2018 USD ($)	Sep. 30, 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 292 days
Finance Lease, Weighted Average Remaining Lease Term (Year)	1 year 73 days
Operating Lease, Right-of-Use Asset	$ 1,040,000		$ 1,177,000			$ 1,300,000
Operating Lease, Liability, Total	1,354,000					$ 1,800,000
Operating Lease, Cost	663,000
Operating Lease, Cost	612,000
Short-term Lease, Cost	51,000
Variable Lease, Cost	0
Operating Lease, Payments	$ 778,000
Operating Leases, Rent Expense, Net, Total		$ 809,000
SAVSU [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Operating Lease Right-of-use Asset				$ 232,000	$ 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