Note 1 - Significant Accounting Policies and Concentrations of Risk - Summary of Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Receivables	$ 8,243	$ 22,146
Billed Revenues [Member]
Receivables	2,816	6,760
Unbilled Revenues [Member]
Receivables	5,427	15,386
US Department of Health and Human Services [Member]
Receivables	5,402	16,376
US Department of Health and Human Services [Member] | Billed Revenues [Member]
Receivables		1,353
US Department of Health and Human Services [Member] | Unbilled Revenues [Member]
Receivables	5,402	15,023
Shionogi and Co. Ltd [Member]
Receivables	2,041	1,340
Shionogi and Co. Ltd [Member] | Billed Revenues [Member]
Receivables	2,037	1,336
Shionogi and Co. Ltd [Member] | Unbilled Revenues [Member]
Receivables	4	4
Green Cross Corporation [Member]
Receivables	761	2,932
Green Cross Corporation [Member] | Billed Revenues [Member]
Receivables	740	2,924
Green Cross Corporation [Member] | Unbilled Revenues [Member]
Receivables	21	8
Mundipharma International Holdings Limited [Member]
Receivables	39	56
Mundipharma International Holdings Limited [Member] | Billed Revenues [Member]
Receivables	$ 39	56
Seqirus UK Limited [Member]
Receivables		1,442
Seqirus UK Limited [Member] | Billed Revenues [Member]
Receivables		1,091
Seqirus UK Limited [Member] | Unbilled Revenues [Member]
Receivables		$ 351