Note 4 - Fair Value Measurements - Quantitative Information for Fair Value Measurement of Level 3 (Details) $ in Thousands	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Fair value	$ 3,900	$ 11,000
MIP-1095 Commercialization [Member]
Fair value	$ 500	$ 450
MIP-1095 Commercialization [Member] | Measurement Input, Probability of Success [Member]
Measurement input	0.18	0.18
MIP-1095 Commercialization [Member] | Measurement Input, Period of Expected Milestone Achievement [Member]
Measurement input	2,026	2,026
MIP-1095 Commercialization [Member] | Measurement Input, Discount Rate [Member]
Measurement input	0.1	0.1
AZEDRA Commercialization [Member]
Fair value		$ 7,050
AZEDRA Commercialization [Member] | Measurement Input, Probability of Success [Member]
Measurement input		0.9
AZEDRA Commercialization [Member] | Measurement Input, Period of Expected Milestone Achievement [Member]
Measurement input		2,019
AZEDRA Commercialization [Member] | Measurement Input, Discount Rate [Member]
Measurement input		0.1
The 1404 Commercialization [Member]
Fair value	$ 300
The 1404 Commercialization [Member] | Measurement Input, Probability of Success [Member]
Measurement input	0.43
The 1404 Commercialization [Member] | Measurement Input, Period of Expected Milestone Achievement [Member] | Minimum [Member]
Measurement input	2,022
The 1404 Commercialization [Member] | Measurement Input, Period of Expected Milestone Achievement [Member] | Maximum [Member]
Measurement input	2,035
The 1404 Commercialization [Member] | Measurement Input, Discount Rate [Member]
Measurement input	0.1
Net sales targets [Member]
Fair value	$ 3,100	$ 3,500
Net sales targets [Member] | Measurement Input, Probability of Success [Member] | Minimum [Member]
Measurement input	0.18	0.18
Net sales targets [Member] | Measurement Input, Probability of Success [Member] | Maximum [Member]
Measurement input	0.9	0.9
Net sales targets [Member] | Measurement Input, Discount Rate [Member]
Measurement input	0.1	0.1