Note 4 - Collaboration and License Agreement (Details Textual) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended	32 Months Ended
	Nov. 06, 2020	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Jun. 30, 2023
Revenue from Contract with Customer, Excluding Assessed Tax, Total		$ 1,274	$ 1,615	$ 2,764	$ 2,707
3D Medicines, Inc [Member]
Proceeds from Collaborators						$ 15,000	$ 27,000
Collaborative Agreement, Maximum Clinical Development, Regulatory and Commercial Milestone Payments	$ 207,000
Collaborative Agreement, Royalty, Period After First Commercial Sale of Product (Year)	10 years
Revenue, Remaining Performance Obligation, Amount		27,000		27,000			27,000
Contract with Customer, Liability		2,600		2,600		$ 5,000	2,600
Contract with Customer, Liability, Revenue Recognized				$ 1,000
Service Period (Year)				1 year 1 month 6 days
3D Medicines, Inc [Member] | Research and Development Services [Member]
Revenue, Remaining Performance Obligation, Amount		14,500		$ 14,500			14,500
Revenue from Contract with Customer, Excluding Assessed Tax, Total				2,400	2,700
3D Medicines, Inc [Member] | License [Member]
Revenue, Remaining Performance Obligation, Amount		$ 12,500		12,500			$ 12,500
Revenue from Contract with Customer, Excluding Assessed Tax, Total				$ 0	$ 0