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Collaboration Agreements, License Agreement and Revenues - Drug Product Revenue - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Deferred Revenue	$ 7,325					$ 7,325		$ 12,739
Drug product revenue recognized	40,134			$ 15,735		120,614	$ 106,367
Other long-term liabilities	4,255					4,255		6,440
Astra Zeneca Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenue recognized as drug product revenue						68,347
Drug Product Revenue, Net [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,320			(4,077)		17,701	4,610
Drug Product Revenue, Net [Member] \| Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	1,300					17,700
Drug Product Revenue, Net [Member] \| Europe [Member] \| Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	625			236		1,465	1,313
Drug Product Revenue, Net [Member] \| Europe [Member] \| Astellas Europe Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized						28,700
Accrued liabilities								57,400
Drug Product Revenue, Net [Member] \| Europe [Member] \| Astellas Europe Agreement [Member] \| Royalty Revenue [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Royalty revenue recognized as drug product revenue	600					1,500
Drug Product Revenue, Net [Member] \| Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized		$ 14,400	$ 1,700		$ 9,800
Drug Product Revenue, Net [Member] \| Japan [Member] \| Astellas Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	695			(4,313)		16,236	$ 3,297
Accrued liabilities	600					600		$ 6,500
Other long-term liabilities	700					700
Drug Product Revenue, Net [Member] \| API Shipment [Member] \| Japan [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized	700	$ 600		$ 4,300	$ 2,200
Bulk Drug Product [Member] \| Astra Zeneca Agreements [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Drug product revenue recognized						11,200
Bulk Drug Product [Member] \| Europe [Member] \| Astellas Europe Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accrued liabilities	$ 28,600					$ 28,600