Note 16 - Stock-based Compensation - Stock Option Award Activity (Details) - USD ($)		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Options outstanding (in shares)		1,552
Options outstanding, weighted average exercise price (in dollars per share)	[1]	$ 556.13
Options outstanding, weighted average remaining contractual term (Year)		9 years 7 months 6 days	5 years 7 months 6 days
Number of awards issued/granted (in shares)		4,762,004	0	0
Granted, weighted average exercise price (in dollars per share)	[1]	$ 4.63
Canceled or forfeited (in shares)		(17,188)
Canceled or forfeited, weighted average exercise price (in dollars per share)	[1]	$ 5,693.43
Exercised (in shares)		0
Exercised, weighted average exercise price (in dollars per share)	[1]	$ 0
Options outstanding (in shares)		4,746,368	1,552
Options outstanding, weighted average exercise price (in dollars per share)	[1]	$ 5.11	$ 556.13
Options outstanding, aggregate intrinsic value		$ 0
Options exercisable (in shares)		1,515
Options exercisable, weighted average exercise price (in dollars per share)	[1]	$ 429.54
Options exercisable, weighted average remaining contractual term (Year)		4 years 7 months 6 days
Options exercisable, aggregate intrinsic value		$ 0
Options vested and expected to vest (in shares)		4,746,368
Options vested and expected to vest, weighted average exercise price (in dollars per share)	[1]	$ 5.11
Options vested and expected to vest, weighted average remaining contractual term (Year)		9 years 7 months 6 days
Options vested and expected to vest, aggregate intrinsic value		$ 0

[1] Exercise price of options outstanding range from $4 to $56,460 as of December 31, 2021.