Note 16 - Warrants (Details Textual) - USD ($) $ / shares in Units, $ in Thousands							12 Months Ended
	Mar. 10, 2020	Feb. 24, 2020	Sep. 12, 2017	Apr. 28, 2017	Aug. 14, 2015	Sep. 26, 2014	Mar. 09, 2021	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2020	May 10, 2017
Number of Units Sold (in shares)				24,900,000
Number of Shares in Each Unit (in shares)				0.077
Equity Offering, Price Per Unit (in dollars per share)				$ 1.00
Stock issued During Period, Value, Exchange of Shares for Warrants								$ 2,470
Preferred Stock Dividends and Other Adjustments, Total								400
Stock Warrants [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding								$ 200	$ 200
Series A Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 13.00
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				0.077
Series B Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)				$ 13.00				$ 0.35		$ 0.35
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				0.058
Warrants, Exercisable Right, Limitation Percentage								4.99%
Outstanding Voting Stock Acquisition Threshold, Percentage to Assume Warrant Obligations								50.00%
Class of Warrant or Right, Outstanding (in shares)		3,638,780								567,660
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)								567,660
Series B Warrant [Member] | Exchange Agreement [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)		0.61
Class of Warrant or Right, Outstanding (in shares)		3,373,900
Stock issued During Period, Shares, Exchange of Shares for Warrants (in shares)		2,040,757
Stock issued During Period, Value, Exchange of Shares for Warrants		$ 2,500
Series C Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)	25,367,646
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.68
Class of Warrant or Right, Exercised During Period (in shares)							25,235,970
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	1
Series D Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)	25,367,646
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)	$ 0.68
Class of Warrant or Right, Exercised During Period (in shares)							24,094,899
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)	1
Warrants Issued in Connection with the Innovatus Loan Agreement [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)											$ 13.00
Warrants and Rights Outstanding, Term (Year)											5 years
Class of Warrant or Right, Exercised During Period (in shares)								0	0
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)											95,750
Service Warrants [Member]
Class of Warrant or Right, Issued During Period (in shares)			73,076
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)			$ 13.00
Warrants and Rights Outstanding, Term (Year)			10 years
Class of Warrant or Right, Exercised During Period (in shares)								0	15,385
Class of Warrant or Right, Percentage of Vesting, Date of Execution Agreement			25.00%
Class of Warrant or Right, Percentage of Vesting, Completion of Hiring the Sales Team			50.00%
Class of Warrant or Right, Percentage of Vesting, Achieving Cumulative Product Revenue			25.00%
Class of Warrant or Right, Vesting, Cumulative Product Revenue			$ 15,000
SVB Loan Agreement [Member] | Warrants Issued in Connection with First Tranche Borrowings [Member]
Class of Warrant or Right, Issued During Period (in shares)						2,948
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)						$ 52.20
Warrants and Rights Outstanding, Term (Year)						7 years
Class of Warrant or Right, Exercised During Period (in shares)								0	0
SVB Loan Agreement [Member] | Second Warrants Issued in Connection with First Tranche Borrowings [Member]
Class of Warrant or Right, Issued During Period (in shares)					8,684
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)					$ 40.30
Warrants and Rights Outstanding, Term (Year)					7 years
Class of Warrant or Right, Exercised During Period (in shares)								0	0