Note 9 - Operating Leases (Details Textual) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Operating Lease, Weighted Average Discount Rate, Percent	9.50%	9.50%
Operating Lease, Expense	$ 0.6	$ 1.1
Lessee, Operating Lease, Renewal Term			5 years
Operating Lease, Payments	$ 0.5	$ 1.0
Minimum [Member]
Lessee, Operating Lease, Remaining Lease Term		1 year
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term		11 years 109 days