Note 10 - Equity, Share-based Compensation, Warrants and Securities Offerings - Restricted Stock Unit Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Nonvested, weighted average expense period (Year)	2 years 10 months 24 days	1 year 4 months 24 days	1 year 1 month 6 days
Restricted Stock Units (RSUs) [Member]
Nonvested, shares issued (in shares)	126,603	149,540
Nonvested, unrecognized stock compensation	$ 658	$ 730
Nonvested, average grant date fair value (in dollars per share)	$ 5.20	$ 4.88
Nonvested, weighted average expense period (Year)	2 years 9 months 18 days	10 months 24 days	1 year 4 months 24 days
Granted, nonvested, shares issued (in shares)	527,871	82,469
Granted, unrecognized stock compensation	$ 1,680	$ 796
Granted, average grant date fair value (in dollars per share)	$ 3.18	$ 9.65
Granted, weighted average expense period (Year)	2 years 8 months 12 days	1 year
Granted, unrecognized stock compensation	$ 1,680	$ 796
Forfeited, shares issued (in shares)	(11,744)	(291)
Forfeited, unrecognized stock compensation	$ (68)	$ (3)
Forfeited, average grant date fair value (in dollars per share)	$ 5.77	$ 10.31
Forfeited, weighted average expense period (Year)	1 year 1 month 6 days	8 months 12 days
Vested with Service, shares issued (in shares)	(275,912)	(105,115)
Expensed, unrecognized stock compensation	$ (1,160)	$ (865)
Granted, weighted average expense period (Year)	2 years 8 months 12 days	1 year
Before modification, shares issued (in shares)	(17,050)
Before modification, unrecognized stock compensation	$ (150)
Before modification, average grant date fair value (in dollars per share)	$ 8.77
Before modification, weighted average expense period (Year)	7 months 6 days
After modification, shares issued (in shares)	17,050
After modification	$ 64
After modification, average grant date fair value (in dollars per share)	$ 3.73
Nonvested, shares issued (in shares)	366,818	126,603	149,540
Nonvested, unrecognized stock compensation	$ 1,024	$ 658	$ 730
Nonvested, average grant date fair value (in dollars per share)	$ 2.79	$ 5.20	$ 4.88
Vested, balance (in shares)	86,505	38,640
Vested with service (in shares)	275,912	105,115
Issued at vesting (in shares)	(83,725)	(57,250)
Issued at termination of service (in shares)	(53,967)
Vested, balance (in shares)	224,725	86,505	38,640
Stock Units Issued (SUI) [Member]
Nonvested, shares issued (in shares)	0	0
Nonvested, unrecognized stock compensation	$ 0	$ 0
Nonvested, average grant date fair value (in dollars per share)	$ 0	$ 0
Nonvested, weighted average expense period (Year)	2 years 8 months 12 days
Granted, nonvested, shares issued (in shares)	160,000	0
Granted, unrecognized stock compensation	$ 216	$ 0
Granted, average grant date fair value (in dollars per share)	$ 1.35	$ 0
Granted, weighted average expense period (Year)	3 years
Granted, unrecognized stock compensation	$ 216	$ 0
Forfeited, shares issued (in shares)	0	0
Forfeited, unrecognized stock compensation	$ 0	$ 0
Forfeited, average grant date fair value (in dollars per share)	$ 0	$ 0
Vested with Service, shares issued (in shares)	0	0
Expensed, unrecognized stock compensation	$ (15)	$ 0
Granted, weighted average expense period (Year)	3 years
Before modification, shares issued (in shares)	0
Before modification, unrecognized stock compensation	$ 0
Before modification, average grant date fair value (in dollars per share)	$ 0
After modification, shares issued (in shares)	0
After modification	$ 0
After modification, average grant date fair value (in dollars per share)	$ 0
Nonvested, shares issued (in shares)	160,000	0	0
Nonvested, unrecognized stock compensation	$ 201	$ 0	$ 0
Nonvested, average grant date fair value (in dollars per share)	$ 1.26	$ 0	$ 0
Vested with service (in shares)	(0)	(0)