Revenue Recognition - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2022	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenue		$ 6,933	$ 23,003	$ 13,098	$ 27,793
License and milestone fees
Disaggregation of Revenue [Line Items]
Total revenue			15,000		15,000
License and milestone fees \| Vifor Fresenius Medical Care Renal Pharma Ltd. [Member]
Disaggregation of Revenue [Line Items]
Total revenue			15,000		15,000
Collaborative revenue
Disaggregation of Revenue [Line Items]
Total revenue		5,410	8,003	8,160	8,003
Collaborative revenue \| CSL Vifor Profit Sharing [Member]
Disaggregation of Revenue [Line Items]
Total revenue		5,410	8,003	8,160	8,003
Commercial supply revenue
Disaggregation of Revenue [Line Items]
Total revenue		1,400		4,591	4,790
Commercial supply revenue \| CSL Vifor [Member]
Disaggregation of Revenue [Line Items]
Total revenue		1,400		4,591	4,790
Commercial Supply Revenue With No Associated Costs Of Goods Sold [Member] \| CSL Vifor [Member]
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,295		0
Clinical compound revenue
Disaggregation of Revenue [Line Items]
Total revenue				99
Clinical compound revenue \| Maruishi Pharmaceutical Co., Ltd. [Member]
Disaggregation of Revenue [Line Items]
Total revenue		0	0	99	0
Royalty revenue
Disaggregation of Revenue [Line Items]
Total revenue		123		248
Royalty revenue \| CSL Vifor [Member]
Disaggregation of Revenue [Line Items]
Total revenue			$ 0		$ 0
Royalty revenue \| CSL Vifor [Member] \| CSL Vifor Kapruvia [Member]
Disaggregation of Revenue [Line Items]
Total revenue		$ 123		$ 248