Commitments and Contingencies - Additional Information (Details)						1 Months Ended					3 Months Ended			9 Months Ended
	Feb. 10, 2021	Sep. 04, 2020	Apr. 02, 2020	Apr. 09, 2019	Jan. 01, 2017 USD ($)	Feb. 28, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020	Feb. 28, 2019 USD ($)	Jul. 31, 2016 USD ($) ft²	Sep. 30, 2022 USD ($) ft² extensionOption	Mar. 31, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) ft² extensionOption	Sep. 30, 2021 USD ($)	Nov. 30, 2020 ft²	Apr. 30, 2018 ft²
Commitments And Contingencies [Line Items]
Operating lease, cost											$ 1,800,000		$ 1,700,000	$ 5,400,000	$ 5,000,000
Operating lease, payments											1,800,000		1,800,000	5,500,000	5,300,000
Inventory adjustments to previous reserves											5,800,000	$ 3,200,000		14,800,000
Increase (decrease) in purchase commitments											13,200,000	$ (800,000)		12,422,000	15,376,000
Total remaining contract costs											4,600,000			4,600,000
Contract cost incurred in research and development activities														176,300,000
Supply Agreement, Patheon Inc.
Commitments And Contingencies [Line Items]
Minimum purchase commitment											3,200,000			3,200,000
BioVectra Inc
Commitments And Contingencies [Line Items]
Long-term minimum purchase commitment renewal term		1 year
Cost of purchased minimum quantity product											74,800,000			74,800,000
Siegfried Evionnaz SA
Commitments And Contingencies [Line Items]
Cost of purchased minimum quantity product											$ 9,900,000			$ 9,900,000
Purchase commitment, option to extend, prior notice period														12 months
Esteve Química, S.A
Commitments And Contingencies [Line Items]
Initial term of supply agreement				4 years
Long-term minimum purchase commitment														$ 26,900,000
STA Pharmaceutical Hong Kong Limited
Commitments And Contingencies [Line Items]
Long-term minimum purchase commitment														$ 19,200,000
Minimum purchase commitment, initial term			4 years
WuXi STA
Commitments And Contingencies [Line Items]
Minimum purchase commitment, initial term	4 years
Long-term purchase commitment, fixed price, period	12 months
Minimum
Commitments And Contingencies [Line Items]
Operating lease, incremental borrowing rates based on remaining lease term											6.65%			6.65%
Operating lease, remaining lease term											3 years 11 months 12 days			3 years 11 months 12 days
Maximum
Commitments And Contingencies [Line Items]
Operating lease, incremental borrowing rates based on remaining lease term											7.25%			7.25%
Operating lease, remaining lease term											8 years 10 months 2 days			8 years 10 months 2 days
Keryx Biopharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Preliminary fair value of the off-market element							$ 76,700,000				$ 74,300,000			$ 74,300,000
Cambridge
Commitments And Contingencies [Line Items]
Area of property leased (in square feet) | ft²										45,362						65,167
Annual lease expense										$ 242,000
Monthly lease expense					$ 22,000
Cambridge | Letter of Credit | Other Assets
Commitments And Contingencies [Line Items]
Total security deposit in connection with lease											$ 1,600,000			$ 1,600,000
Cambridge | Office Space
Commitments And Contingencies [Line Items]
Area of property leased (in square feet) | ft²																	19,805
Monthly lease expense							$ 48,000		$ 135,000
Operating lease, free monthly rent, period								2 months
Lease period, number of extension options | extensionOption											1			1
Lease extension period											5 years			5 years
Boston | Keryx Biopharmaceuticals, Inc. | Letter of Credit | Other Assets
Commitments And Contingencies [Line Items]
Total security deposit in connection with lease											$ 1,400,000			$ 1,400,000
Boston | Office Space
Commitments And Contingencies [Line Items]
Area of property leased (in square feet) | ft²											27,300			27,300
Monthly lease expense						$ 200,122								$ 136,000
Operating lease, free monthly rent, period						5 months
Operating lease, annual rent escalation, percentage						2.00%
Operating lease, allowance for leasehold improvements						$ 1,954,680
Boston | Office Space | Keryx Biopharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Lease period, number of extension options | extensionOption											1			1
Lease extension period											5 years			5 years
Sublease rental income											$ 500,000		$ 400,000	$ 1,400,000	$ 1,300,000