Note 15 - Revenue Recognition (Details Textual) - USD ($) $ in Thousands			3 Months Ended								12 Months Ended
	Mar. 08, 2023	Jul. 06, 2021	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Contract with Customer, Performance Obligation Satisfied in Previous Period											$ 19,200	$ 21,500
Accrued Expense, Payor Overpayment Reimbursement, Liability			$ 3,100				$ 1,800				3,100	1,800
Contract with Customer, Liability, Revenue Recognized											131
Revenue from Contract with Customer, Excluding Assessed Tax			$ 181,905	$ 178,595	$ 265,418	$ 237,577	$ 185,340	$ 179,744	$ 309,893	$ 329,219	863,495	1,004,196	$ 1,774,718
CAMP4 [Member]
Revenue from Contract with Customer, Excluding Assessed Tax		$ 1,500
Merck Agreement [Member] | Merck Sharp & Dohme LLC [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 50,000
Rayaldee [Member]
Contract with Customer, Liability, Revenue Recognized											31,000	27,300	27,000
Revenue from Contract with Customer, Excluding Assessed Tax											67,547	59,557	64,301
Transfer of Intellectual Property and Other [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											180,663	105,721	25,842
Transfer of Intellectual Property and Other [Member] | Pfizer Inc. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											4,100	9,300	10,800
Transfer of Intellectual Property and Other [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax												3,000
Transfer of Intellectual Property and Other [Member] | NICOYA Macau Limited [Member]
Revenue from Contract with Customer, Excluding Assessed Tax												2,500	5,000
Transfer of Intellectual Property and Other [Member] | LeaderMed [Member]
Revenue from Contract with Customer, Excluding Assessed Tax													1,000
Transfer of Intellectual Property and Other [Member] | CAMP4 [Member]
Revenue from Contract with Customer, Excluding Assessed Tax													$ 4,900
Transfer of Intellectual Property and Other [Member] | Milestone Payments [Member] | Pfizer Inc. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											90,000	85,000
Transfer of Intellectual Property and Other [Member] | Milestone Payments [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											22,600	$ 4,400
Transfer of Intellectual Property and Other [Member] | Merck Agreement [Member] | Merck Sharp & Dohme LLC [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											50,000
Transfer of Intellectual Property and Other [Member] | Development and License Agreement [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											7,000
Transfer of Intellectual Property and Other [Member] | Development and License Agreement [Member] | NICOYA Macau Limited [Member]
Revenue from Contract with Customer, Excluding Assessed Tax											$ 2,500