Schedule of Revenue from Collaborations and Services (Detail) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
		Jun. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			$ 32,825	$ 22,211	$ 63,711	$ 62,927
United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			16,529	12,313	24,268	33,475
License Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			393	12,313	1,949	33,475
Commercial Supply Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			9,916		15,795
Collaborations and services
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			10,346	12,458	18,380	35,099
Collaborations and services | License Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services	[1]		393	12,313	1,949	33,475
Collaborations and services | Commercial Supply Agreement | United Therapeutics Corporation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services	[2]		9,916		15,795
Collaborations and services | License and Distribution Agreement | Cipla Ltd
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services			$ 37	37	110	110
Collaborations and services | Other
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Total revenue from collaborations and services				77	200	161
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	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				$ 31	$ 1	$ 206

[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.