DEBT (Details) $ in Thousands					3 Months Ended		9 Months Ended
	Jul. 15, 2022 USD ($)	Dec. 10, 2020 USD ($)	Nov. 25, 2019 USD ($)	Nov. 11, 2019 USD ($) tranche	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)	Oct. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Line of Credit Facility [Line Items]
Debt extinguishment loss					$ 0	$ 906	$ 0	$ 906
Embedded debt derivative					760		760			$ 760
Gain from decrease in the fair value of the embedded debt derivative								1,100
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche A and B
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 100,000
Line of credit, maximum borrowing capacity, number of available tranches | tranche				2
Payment for debt prepayment	$ 25,000
Payment for debt prepayment premium, including accrued and unpaid interest	$ 500
Debt extinguishment loss						900
Principal outstanding					43,000		43,000
Interest expense					1,400	$ 2,100	4,700	$ 7,500
Unamortized discount and issuance costs					400		400
Term loan, principal payment					0		24,000
Term loan, maturity term, potential reduction (up to)				1 year
Term loan, amortization period, potential reduction (up to)				1 year
Prepayment premium percentage on principal if prepaid before maturity date				0.50%
Minimum net sales threshold, trailing period				12 months
Minimum net sales threshold				$ 85,000
Embedded debt derivative					$ 800		$ 800			$ 800
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche A and B | Subsequent Event
Line of Credit Facility [Line Items]
Principal outstanding									$ 35,000
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche A and B | Debt Instrument, Quarterly Periodic Payment, Period One
Line of Credit Facility [Line Items]
Term loan, first quarterly principal payment due in				33 months
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche A and B | Secured Overnight Financing Rate (SOFR)
Line of Credit Facility [Line Items]
Basis spread on variable rate	7.50%
Interest rate					11.15%		11.15%
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche A
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 80,000
Proceeds from line of credit, net			$ 77,300
Debt fees and expenses			$ 2,700
Biopharma Credit Investments V (Master) LP | Keryx | Term Loan | Collateral Agent, Pharmakon | Tranche B
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity				$ 20,000
Proceeds from line of credit, net		$ 20,000
Payment for debt prepayment	$ 20,000