Note 16 - Income Taxes - Reconciliation of Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
U.S. federal taxes at statutory rate	21.00%	21.00%
State taxes (net of federal benefit)	0.40%	0.60%
Foreign rate differential	(2.60%)	3.10%
Global intangible low-taxed income		(8.80%)
Permanently non-deductible items	(3.70%)	(2.50%)
Tax credits	1.70%	2.10%
Change in valuation allowance	194.20%	(20.40%)
Tax attributes write-off due to change in control	(208.30%)
Prior year true-up	(0.90%)
NOL and credit adjustments		(3.80%)
Bargain purchase gain		8.10%
Other	(4.50%)
Provision for income taxes	(2.70%)	(0.60%)