Note 11 - Fair Value Accounting - Derivative Liabilities (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Change in fair value included in earnings	$ 1,342,000	$ 535,000	$ 16,558,000	$ 369,000
Fair value at end of period	7,486,000		7,486,000
Fair Value, Inputs, Level 3 [Member]
Fair value at beginning of period	8,925,000	535,000	24,128,000	369,000
Change in fair value included in earnings	(1,342,000)	(535,000)	(16,558,000)	(369,000)
Fair value at end of period	7,486,000	0	7,486,000	0
Fair Value, Inputs, Level 3 [Member] | Series C Preferred Stock [Member]
Derivative liability from issuance	0	0	0	0
Decrease in derivative liability from conversions	0	0	0	0
Fair Value, Inputs, Level 3 [Member] | Series D Preferred Stock [Member]
Derivative liability from issuance	84,000	0	500,000	0
Decrease in derivative liability from conversions	$ (181,000)	$ 0	$ (584,000)	$ 0