Note 12 - Leases (Details Textual)	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Operating Lease, Weighted Average Discount Rate, Percent	6.50%	6.50%
Finance Lease, Weighted Average Discount Rate, Percent	8.10%	8.10%
Operating Lease, Weighted Average Remaining Lease Term	2 years	2 years
Finance Lease, Weighted Average Remaining Lease Term	1 year 255 days	1 year 255 days
Operating Lease, Cost	$ 142,000	$ 285,000
Operating Lease, Payments	$ 186,000	$ 371,000
Bothell, Washington Headquarters [Member]
Lessee, Operating Lease, Renewal Term	5 years	5 years