Revenue Recognition - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended			3 Months Ended		8 Months Ended	9 Months Ended
	Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Collaboration Arrangement [Line Items]
Accounts receivable, net - related party				$ 9,623		$ 9,623	$ 9,623
Total revenue				10,813	$ 20,272		38,606	$ 22,207
Price per share					$ 15.23			$ 15.23
Research and development expense				24,691	$ 15,514		65,869	$ 59,870
Commercial Supply Revenue
Collaboration Arrangement [Line Items]
Total revenue				3,370			8,160
License and Milestone Fees
Collaboration Arrangement [Line Items]
Total revenue					20,031		15,000	21,223
Collaborative Revenue
Collaboration Arrangement [Line Items]
Total revenue				7,443			15,446	706
Clinical Compound Revenue
Collaboration Arrangement [Line Items]
Total revenue					241			278
Vifor Agreement No 2 [Member] | License and Milestone Fees | Regulatory Milestones [Member]
Collaboration Arrangement [Line Items]
Total revenue				0
Proceeds from milestone payments	$ 15,000		$ 15,000
Vifor, Vifor International, Maruishi and CKDP Agreements [Member]
Collaboration Arrangement [Line Items]
Accounts receivable, net - related party									$ 0
Other contract Assets				0		0	0		0
Other contract liabilities				0		0	0		$ 0
Maruishi Agreement [Member] | License and Milestone Fees
Collaboration Arrangement [Line Items]
Total revenue				0	0		0	1,192
Maruishi Agreement [Member] | Collaborative Revenue
Collaboration Arrangement [Line Items]
Total revenue				0	0		0	706
Maruishi Agreement [Member] | Clinical Compound Revenue
Collaboration Arrangement [Line Items]
Total revenue								37
Maruishi Pharmaceutical Co., Ltd. [Member] | Clinical Compound Revenue
Collaboration Arrangement [Line Items]
Total revenue				0	0		0	37
Research and development expense								33
Vifor International Ltd. [Member] | Regulatory Milestones [Member]
Collaboration Arrangement [Line Items]
Proceeds from the sale of common stock			$ 50,000
Common stock, shares issued			3,282,391
Price per share			$ 15.23
Percentage of premium on common stock investment			20.00%
Stock Issuance Price Measurement Period			30 days
Vifor International Ltd. [Member] | License and Milestone Fees
Collaboration Arrangement [Line Items]
Total revenue					5,031			5,031
Vifor [Member]
Collaboration Arrangement [Line Items]
Accounts receivable, net - related party				9,623		9,623	9,623
Vifor [Member] | Commercial Supply Revenue
Collaboration Arrangement [Line Items]
Total revenue				3,370			8,160
Vifor [Member] | Commercial Supply Revenue With No Associated Costs Of Goods Sold [Member]
Collaboration Arrangement [Line Items]
Revenue		$ 2,295
Cost of goods sold		$ 0
Vifor [Member] | Commercial Supply Revenue With Associated Costs Of Goods Sold [Member]
Collaboration Arrangement [Line Items]
Revenue						5,865
Cost of goods sold				3,055		$ 5,136
Vifor [Member] | Collaborative Revenue
Collaboration Arrangement [Line Items]
Total revenue				7,443	0		15,446	0
Vifor [Member] | Vifor Agreement [Member] | Clinical Compound Revenue
Collaboration Arrangement [Line Items]
Total revenue				$ 0	241		$ 0	241
Research and development expense					$ 228			$ 228