Note 13 - Revenue Recognition (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 1,500	$ 500
Accrued Expense, Payor Overpayment Reimbursement, Liability	2,400		$ 2,000
Revenue from Contract with Customer, Excluding Assessed Tax	149,952	173,686
Rayaldee [Member]
Contract with Customer, Liability, Revenue Recognized	6,300	6,900
Revenue from Contract with Customer, Excluding Assessed Tax	13,110	15,157
Transfer of Intellectual Property and Other [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	12,266	8,749
Increase (Decrease), Revenue from Contract with Customer, Excluding Assessed Tax	3,500
Transfer of Intellectual Property and Other [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	4,500	5,600
Transfer of Intellectual Property and Other [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] | Development and License Agreement [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 7,000	$ 2,200