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Collaboration and Licensing Agreements - Additional Information (Detail) $ / shares in Units, $ in Thousands			1 Months Ended			12 Months Ended
	Oct. 15, 2020 USD ($) item	May 17, 2018 USD ($) item $ / shares shares	Oct. 31, 2021 USD ($) $ / shares shares	Oct. 31, 2020 USD ($) $ / shares shares	Apr. 30, 2013 item	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from the sale of common stock								$ 136,498
Purchase of common stock value								136,498
Revenue from contract with customer						$ 23,028	$ 135,082	19,886
Cost of goods sold						0
Collaborative Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						706
Commercial Supply Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						701
Clinical Compound Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						$ 398	643	140
Vifor Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net profit sharing				60.00%
Number of days to terminate agreement						60 days
Cost of goods sold						$ 0
Vifor Agreement [Member] \| License [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of performance obligations for revenue recognized \| item	1
Revenue from contract with customer							111,551
Vifor Agreement [Member] \| Commercial Supply Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						701
VFMCRP Agreement [Member] \| Clinical Compound Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						361	115
Cost of clinical compound related to R&D expense						343	108
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable, non-creditable upfront payment		$ 50,000
Common stock, shares issued \| shares		1,174,827
Purchase of common stock value		$ 20,000
Purchase common stock per share amount \| $ / shares		$ 17.024
Closing prices of company common stock description		over a pre-determined average closing price of the Company’s common stock.
Premium from sale of stock		$ 5,444
Deferred revenue		$ 55,444
Number of combined performance obligations for revenue recognized \| item		1
Number of performance obligations for revenue recognized \| item		2
Number of days to terminate agreement		60 days
Termination notice effective period		12 months
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Clinical Compound Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						361	115
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from milestone payments			$ 15,000
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Regulatory and Commercial Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments		$ 455,000
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments						15,000
Vifor Fresenius Medical Care Renal Pharma Ltd. [Member] \| Maximum [Member] \| Tiered Commercial Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments						440,000
Maruishi Pharmaceutical Co., Ltd. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Number of performance obligations for revenue recognized \| item					2
Cost of clinical compound related to R&D expense						33	476	126
Maruishi Pharmaceutical Co., Ltd. [Member] \| Collaborative Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						706
Maruishi Pharmaceutical Co., Ltd. [Member] \| Clinical Compound Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						37	$ 528	$ 140
Vifor International Ltd. [Member]
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Number of performance obligations for revenue recognized \| item	1
Vifor International Ltd. [Member] \| Commercial Supply Revenue
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue from contract with customer						701
Vifor International Ltd. [Member] \| Regulatory and Commercial Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Proceeds from the sale of common stock	$ 50,000
Vifor International Ltd. [Member] \| Vifor Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of net profit sharing				40.00%
Common stock, shares issued \| shares				2,939,552
Purchase common stock per share amount \| $ / shares				$ 17.0094
Vifor International Ltd. [Member] \| Vifor Agreement [Member] \| License [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Non-refundable, non-creditable upfront payment				$ 100,000
Premium from sale of stock				$ 11,551
Vifor International Ltd. [Member] \| Regulatory Milestones [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Common stock, shares issued \| shares			3,282,391
Proceeds from the sale of common stock			$ 50,000
Purchase common stock per share amount \| $ / shares			$ 15.23
Premium from sale of stock						$ 5,031
Proceeds from milestone payments	$ 50,000
Percentage of premium on common stock investment	20.00%		20.00%
Stock issuance price measurement period	30 days		30 days
Vifor International Ltd. [Member] \| Maximum [Member] \| Sales-based Milestones
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential milestone payments	$ 240,000