Note 7 - Stockholders' Equity - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2023
Outstanding, options (in shares)	22,474
Outstanding, weighted average exercise price (in dollars per share)	$ 85.5
Outstanding, remaining term (Year)	9 years	9 years 6 months
Outstanding, aggregate intrinsic value		$ 0
Granted, options (in shares)	0
Granted, weighted average exercise price (in dollars per share)	$ 0
Exercised, options (in shares)	0
Exercised, weighted average exercise price (in dollars per share)	$ 0
Cancelled/forfeited, options (in shares)	0
Cancelled/forfeited, weighted average exercise price (in dollars per share)	$ 0
Expired, options (in shares)	0
Expired, weighted average exercise price (in dollars per share)	$ 0
Outstanding, options (in shares)	22,474	22,474
Outstanding, weighted average exercise price (in dollars per share)	$ 85.5	$ 85.5
Expected to vest, options (in shares)	16,304
Expected to vest, weighted average exercise price (in dollars per share)	$ 85.5
Expected to vest, remaining term (Year)	9 years
Expected to vest, aggregate intrinsic value	$ 0
Exercisable, options (in shares)	6,170
Exercisable, weighted average exercise price (in dollars per share)	$ 85.5
Exercisable, remaining term (Year)	9 years
Exercisable, aggregate intrinsic value	$ 0