Note 1 - Significant Accounting Policies - Summary of Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Receivables	$ 5,002	$ 4,293
Billed Revenues [Member]
Receivables	3,962	2,714
Unbilled Revenues [Member]
Receivables	1,040	1,579
US Department of Health and Human Services [Member]
Receivables	1,687	1,525
US Department of Health and Human Services [Member] | Billed Revenues [Member]
Receivables	673
US Department of Health and Human Services [Member] | Unbilled Revenues [Member]
Receivables	1,014	1,525
Shionogi and Co. Ltd [Member]
Receivables	1,451	854
Shionogi and Co. Ltd [Member] | Billed Revenues [Member]
Receivables	1,451	854
Shionogi and Co. Ltd [Member] | Unbilled Revenues [Member]
Receivables
Green Cross Corporation [Member]
Receivables	642	904
Green Cross Corporation [Member] | Billed Revenues [Member]
Receivables	642	876
Green Cross Corporation [Member] | Unbilled Revenues [Member]
Receivables		28
Mundipharma International Holdings Limited [Member]
Receivables	21	44
Mundipharma International Holdings Limited [Member] | Billed Revenues [Member]
Receivables	21	44
Mundipharma International Holdings Limited [Member] | Unbilled Revenues [Member]
Receivables
Seqirus UK Limited [Member]
Receivables	1,201	966
Seqirus UK Limited [Member] | Billed Revenues [Member]
Receivables	1,175	940
Seqirus UK Limited [Member] | Unbilled Revenues [Member]
Receivables	$ 26	$ 26