Note 9 - Stockholders' Equity - Stock Option Activity (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Options (in shares)	7,954	7,663
Options, weighted average exercise price (in dollars per share)	$ 1,707.30	$ 2,917.30
Options granted (in shares)		3,100
Options granted, weighted average exercise price (in dollars per share)		$ 16.70
Options expired (in shares)	(448)	(2,550)
Options expired, weighted average exercise price (in dollars per share)	$ 3,061.09	$ 2,725.80
Options forfeited (in shares)	(105)	(259)
Options forfeited, weighted average exercise price (in dollars per share)	$ 1,929.52	$ 3,493.70
Options (in shares)	7,401	7,954
Options, weighted average exercise price (in dollars per share)	$ 1,309.47	$ 1,707.30
Options, weighted average remaining contractual life (Year)	6 years 295 days
Exercisable (in shares)	7,224
Exercisable, weighted average exercise price (in dollars per share)	$ 1,310.25
Exercisable, weighted average remaining contractual life (Year)	6 years 292 days
Vested and expected to vest (in shares)	7,401
Vested and expected to vest, weighted average exercise price (in dollars per share)	$ 1,309.47
Vested and expected to vest, weighted average remaining contractual life (Year)	6 years 295 days