Note 7 - Stock-based Compensation - Schedule of Option Activity (Details) - $ / shares		3 Months Ended	12 Months Ended
		Mar. 31, 2024	Dec. 31, 2023
Balance, options (in shares)	[1]	16,365
Balance, options, weighted average exercise price (in dollars per share)	[1]	$ 110.51
Balance, options, remaining contractual term (Year)		4 years 6 months 25 days	5 years
Options granted (in shares)	[1]	0
Options granted, weighted average exercise price (in dollars per share)	[1]	$ 0
Options exercised (in shares)	[1]	0
Options exercised, weighted average exercise price (in dollars per share)	[1]	$ 0
Options canceled (in shares)	[1]	(426)
Options canceled, weighted average exercise price (in dollars per share)	[1]	$ 93.71
Balance, options (in shares)	[1]	15,939	16,365
Balance, options, weighted average exercise price (in dollars per share)	[1]	$ 110.96	$ 110.51
Exercisable, options3 (in shares)	[1]	15,939
Exercisable, options, weighted average exercise price (in dollars per share)	[1]	$ 110.96
Exercisable, options, remaining contractual term (Year)		4 years 6 months 25 days
Vested and expected to vest, options (in shares)	[1]	15,939
Vested and expected to vest, options, , weighted average exercise price (in dollars per share)	[1]	$ 110.96
Vested and expected to vest, options, remaining contractual term (Year)		4 years 6 months 25 days

[1] The number of options and exercise price per share have been retroactively restated to reflect the one for twelve (1 for 12) reverse stock split, which was effective on March 22, 2024.