Note 2 - Revenue - Summary of Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Total revenues	$ 270,827	$ 157,170	$ 17,812
Torii Pharmaceutical Co., Ltd.
Disaggregation of Revenue [Line Items]
Total revenues	0
Product sales, net
Disaggregation of Revenue [Line Items]
Total revenues	267,710	136,350	3,301
Product sales, net | ORLADEYO
Disaggregation of Revenue [Line Items]
Total revenues	249,689	121,865	133
Product sales, net | RAPIVAB
Disaggregation of Revenue [Line Items]
Total revenues	15,156	7,231	483
Product sales, net | Peramivir
Disaggregation of Revenue [Line Items]
Total revenues	2,865	7,254	2,685
Royalty revenue
Disaggregation of Revenue [Line Items]
Total revenues	2,903	(100)	3,381
Milestone revenue
Disaggregation of Revenue [Line Items]
Total revenues	0	15,000	0
Collaborative and other research and development
Disaggregation of Revenue [Line Items]
Total revenues	214	5,920	11,130
Collaborative and other research and development | U.S. Department of Health and Human Services
Disaggregation of Revenue [Line Items]
Total revenues	$ 190	5,920	9,231
Collaborative and other research and development | Torii Pharmaceutical Co., Ltd.
Disaggregation of Revenue [Line Items]
Total revenues		$ 0	$ 1,899