Commitments and Contingencies - Narrative (Details)					1 Months Ended					3 Months Ended	12 Months Ended
	Dec. 22, 2022 USD ($) quarter_period	Feb. 10, 2021	Apr. 02, 2020	Jan. 01, 2017 USD ($)	Feb. 28, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020	Feb. 28, 2019 USD ($)	Jul. 31, 2016 USD ($) ft²	Dec. 31, 2022 USD ($) ft² extensionOption	Dec. 31, 2022 USD ($) ft² extensionOption	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Nov. 30, 2020 ft²	Apr. 30, 2018 ft²
Commitments And Contingencies [Line Items]
Operating lease, cost											$ 7,100,000	$ 6,700,000	$ 6,700,000
Operating lease, payments											7,200,000	7,100,000	7,000,000
Decrease in purchase commitments										$ 74,300,000	67,618,000	(33,391,000)	(25,114,000)
Contract cost incurred in research and development activities											$ 90,200,000
Supply Agreement, Patheon Inc.
Commitments And Contingencies [Line Items]
Purchase commitment, renewal term											1 year
Purchase commitment, option for non-auto renewal, prior written notice period											18 months
Minimum purchase commitment										3,100,000	$ 3,100,000
Keryx Biopharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Preliminary fair value of the off-market element						$ 76,700,000				0	0	76,700,000
Cambridge
Commitments And Contingencies [Line Items]
Area of property leased | ft²									45,362					65,167
Annual operating lease expense									$ 242,000
Monthly operating lease expense				$ 22,000
BioVectra Inc
Commitments And Contingencies [Line Items]
Long-term purchase commitment, termination amount payable	$ 32,500,000
Long-term purchase commitment, upfront payment termination amount	$ 17,500,000									17,500,000
Long-term purchase commitment, termination amount payable after upfront payment, number of quarterly periods | quarter_period	6
Long-term purchase commitment, termination amount payable after upfront payment, per quarter	$ 2,500,000
Long-term purchase commitment, termination amount payable after upfront payment	$ 15,000,000
Long-term purchase commitment, upfront termination amount classified as cost of goods sold										11,200,000
Long-term purchase commitment, imputed interest on termination amount payable	17.00%
Siegfried Evionnaz SA
Commitments And Contingencies [Line Items]
Cost of purchased minimum quantity product										$ 8,400,000	8,400,000
STA Pharmaceutical Hong Kong Limited
Commitments And Contingencies [Line Items]
Long-term purchase commitment											$ 15,300,000
Long-term purchase commitment, initial term			4 years
WuXi STA
Commitments And Contingencies [Line Items]
Purchase commitment, option to extend, prior notice period		18 months
Long-term purchase commitment, initial term		4 years
Long-term purchase commitment, fixed price, period		12 months
Long-term purchase commitment, option to terminate, prior notice period (at least)		180 days
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 8 months 12 days	3 years 8 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 7 months 2 days	8 years 7 months 2 days
Letter of Credit | Other Current Assets | Keryx Biopharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Total security deposit in connection with lease										$ 1,100,000	$ 1,100,000
Letter of Credit | Other Current Assets | Cambridge
Commitments And Contingencies [Line Items]
Total security deposit in connection with lease										$ 1,600,000	$ 1,600,000
Office Space | Cambridge
Commitments And Contingencies [Line Items]
Area of property leased | ft²															19,805
Monthly operating lease expense						$ 48,000		$ 135,000
Operating lease, free monthly rent, period							2 months
Operating lease period, number of extension options | extensionOption										1	1
Operating lease extension period										5 years	5 years
Office Space | Boston
Commitments And Contingencies [Line Items]
Area of property leased | ft²										27,300	27,300
Monthly operating 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
Office Space | Boston | Keryx Biopharmaceuticals, Inc.
Commitments And Contingencies [Line Items]
Operating lease period, number of extension options | extensionOption										1	1
Operating lease extension period										5 years	5 years
Sublease rent payments received											$ 1,800,000	$ 1,800,000	$ 1,800,000
Lab Space | Cambridge
Commitments And Contingencies [Line Items]
Operating lease period, number of extension options | extensionOption										1	1