Revenue Recognition - Disaggregation of Revenue (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenue		$ 4,866	$ 10,813	$ 17,964	$ 38,606
Maruishi Agreement [Member]
Disaggregation of Revenue [Line Items]
Total revenue		1,449		1,449
License and milestone fees
Disaggregation of Revenue [Line Items]
Total revenue		910		910	15,000
License and milestone fees | Maruishi Agreement [Member]
Disaggregation of Revenue [Line Items]
Total revenue		910	0	910	0
License and milestone fees | Affiliated Entity [Member] | Vifor Fresenius Medical Care Renal Pharma Ltd Agreement [Member]
Disaggregation of Revenue [Line Items]
Total revenue					15,000
Collaborative revenue
Disaggregation of Revenue [Line Items]
Total revenue		2,471	7,443	10,631	15,446
Collaborative revenue | Maruishi Agreement [Member]
Disaggregation of Revenue [Line Items]
Total revenue		539	0	539	0
Collaborative revenue | Affiliated Entity [Member] | CSL Vifor Profit Sharing [Member]
Disaggregation of Revenue [Line Items]
Total revenue		1,932	7,443	10,092	15,446
Commercial supply revenue
Disaggregation of Revenue [Line Items]
Total revenue		1,252	3,370	5,843	8,160
Commercial supply revenue | Affiliated Entity [Member] | CSL Vifor Korsuva [Member]
Disaggregation of Revenue [Line Items]
Total revenue		1,252	3,370	5,843	8,160
Commercial Supply Revenue With No Associated Costs Of Goods Sold [Member] | Affiliated Entity [Member] | CSL Vifor Korsuva [Member]
Disaggregation of Revenue [Line Items]
Total revenue	$ 2,295
Clinical compound revenue
Disaggregation of Revenue [Line Items]
Total revenue		66		165
Clinical compound revenue | Maruishi Agreement [Member]
Disaggregation of Revenue [Line Items]
Total revenue		66	0	165	0
Royalty revenue
Disaggregation of Revenue [Line Items]
Total revenue		167		415
Royalty revenue | Affiliated Entity [Member] | CSL Vifor Kapruvia [Member]
Disaggregation of Revenue [Line Items]
Total revenue		$ 167	$ 0	$ 415	$ 0