Note 1 - Significant Accounting Policies - Summary of Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Receivables	$ 8,504	$ 8,243
Billed Revenues [Member]
Receivables	4,965	2,816
Unbilled Revenues [Member]
Receivables	3,539	5,427
US Department of Health and Human Services [Member]
Receivables	7,480	5,402
US Department of Health and Human Services [Member] | Billed Revenues [Member]
Receivables	3,966	0
US Department of Health and Human Services [Member] | Unbilled Revenues [Member]
Receivables	3,514	5,402
Shionogi and Co. Ltd [Member]
Receivables		2,041
Receivables (payables)	(186)
Shionogi and Co. Ltd [Member] | Billed Revenues [Member]
Receivables		2,037
Receivables (payables)	(190)
Shionogi and Co. Ltd [Member] | Unbilled Revenues [Member]
Receivables		4
Receivables (payables)	4
Green Cross Corporation [Member]
Receivables	1,178	761
Green Cross Corporation [Member] | Billed Revenues [Member]
Receivables	1,157	740
Green Cross Corporation [Member] | Unbilled Revenues [Member]
Receivables	21	21
Mundipharma International Holdings Limited [Member]
Receivables	32	39
Mundipharma International Holdings Limited [Member] | Billed Revenues [Member]
Receivables	32	39
Mundipharma International Holdings Limited [Member] | Unbilled Revenues [Member]
Receivables	$ 0	$ 0