Note 2 - Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Product sales	$ 15,126	$ 5,613	$ 9,966	$ 4,281	$ 3,238	$ 5,317	$ 3,878	$ 3,189	$ 34,986	$ 15,622	$ 11,698
AZEDRA Product Sales [Member
Product sales									1,559
Royalty [Member]
Product sales									16,970	14,908	10,965
License and Other [Member]
Product sales									$ 16,457	$ 714	$ 733