Schedule of Revenue from Collaborations and Services (Detail) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
		Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			$ 18,894	$ 23,280	$ 30,886	$ 40,716
United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			5,697	12,163	7,739	21,163
License Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			698	12,163	1,556	21,163
Commercial Supply Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			4,695		5,879
Collaborations and services
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			5,868	13,304	8,034	22,641
Collaborations and services | License Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services	[1]		698	12,163	1,556	21,163
Collaborations and services | Commercial Supply Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services	[2]		4,695		5,879
Collaborations and services | License and Distribution Agreement | Cipla Ltd
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			36	37	73	73
Collaborations and services | Other
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			114	83	201	83
Collaborations and services | Co-Promotion Agreement | Vertice Pharma LLC
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services		$ 300	$ 325	856	$ 325	1,147
Collaborations and services | Collaboration and License Agreement | Receptor CLA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services				$ 165		$ 175

[1] Amounts consist of revenue recognized for Next-Gen R&D Services and R&D Services and License for the periods presented.

[2] Amount consists of revenue recognized for Manufacturing Services and sales of product to UT for the periods presented.