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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Kyowa Kirin Collaboration and License Agreement - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended	9 Months Ended
	Nov. 20, 2024	Nov. 30, 2024	Sep. 30, 2025	Sep. 30, 2025	Dec. 31, 2024
Kyowa Kirin Collaboration and License Agreement [Line Items]
Current contract liabilities			$ 48,750,000	$ 48,750,000	$ 24,271,000
Long-term contract liabilities			268,854,000	268,854,000	$ 253,906,000
Kyowa Clinical Supply Agreement
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue			500,000	500,000
Kyowa License Agreement
Kyowa Kirin Collaboration and License Agreement [Line Items]
Upfront payment received	$ 330,000,000
Upfront payment received				330,000,000
Unconstrained milestones				75,000,000
Royalties recognized			0	0
Sales based milestones recognized			0	0
Transaction price allocated to performance obligation			405,000,000	405,000,000
Current contract liabilities			48,700,000	48,700,000
Long-term contract liabilities			268,900,000	268,900,000
Kyowa License Agreement \| Maximum
Kyowa Kirin Collaboration and License Agreement [Line Items]
Development regulatory and commercial milestone payments in aggregate	1,161,000,000
Upfront and milestone payments in aggregate	$ 1,491,000,000
Kyowa License Agreement \| Performance Obligations
Kyowa Kirin Collaboration and License Agreement [Line Items]
Contract liability			317,600,000	317,600,000
Kyowa License Agreement \| Development Services for Monotherapy
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue			7,000,000	19,800,000
Transaction price allocated to performance obligation			57,600,000	57,600,000
Kyowa License Agreement \| Development Services in Combination with Other Therapies
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue			5,100,000	10,400,000
Transaction price allocated to performance obligation			120,200,000	120,200,000
Kyowa License Agreement \| Commercialization Services
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue			2,300,000	5,300,000
Transaction price allocated to performance obligation			177,400,000	177,400,000
Kyowa License Agreement \| Cost-share Reimbursements
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue			$ 5,900,000	$ 14,100,000
Kyowa License Agreement \| License
Kyowa Kirin Collaboration and License Agreement [Line Items]
Revenue		$ 49,800,000