Collaborations and Other Arrangements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Oct. 31, 2023	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Costs to obtain or fulfill contract capitalized		$ 0		$ 0
Collaboration revenue		14,245,000	$ 6,957,000	30,872,000	$ 35,892,000
Deferred revenue		29,693,000	50,236,000	29,693,000	50,236,000	$ 38,917,000	$ 60,993,000
Accrued expenses		41,553,000		41,553,000		55,355,000
Regeneron Pharmaceuticals Inc. [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Aggregate transaction price remaining to be recognized		16,300,000		16,300,000
Deferred revenue		17,200,000		17,200,000		26,400,000
Regeneron Pharmaceuticals Inc. [Member] | Related Party [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts receivable		10,200,000		10,200,000		7,200,000
Regeneron Pharmaceuticals Inc. [Member] | Hemophilia Co Co Agreements
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		100,000	4,400,000	100,000	7,600,000
Reimbursements cost		100,000		1,600,000
Regeneron Pharmaceuticals Inc. [Member] | Regeneron Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		7,900,000	5,100,000	4,900,000	9,700,000
Deferred revenue	$ 30,000,000
Collaboration agreement further option extension period	two years
Collaboration term extension period	2026-04
Regeneron Pharmaceuticals Inc. [Member] | Two Thousand Sixteen Regeneron Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		5,000,000	5,200,000	10,100,000	10,300,000
Regeneron Pharmaceuticals Inc. [Member] | Two Thousand Twenty Three Regeneron Amendment [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		0	600,000	0	1,100,000
Regeneron Pharmaceuticals Inc. [Member] | Variable Consideration [Member] | Two Thousand Sixteen Regeneron Agreement [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue				1,800,000
Sparing Vision [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		0	500,000	0	1,100,000
Deferred revenue		12,500,000		12,500,000		12,500,000
Sparing Vision [Member] | Related Party [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Accounts receivable		0		0		600,000
AvenCell [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		21,000,000		21,000,000
Accounts receivable		1,000,000		1,000,000		700,000
Accrued expenses		1,000,000		1,000,000		$ 1,000,000
AvenCell [Member] | Research Materials Shippmet Services [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue				1,000,000
Kyverna Therapeutics Inc [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue		$ 0		$ 0
ONK Therapeutics [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Collaboration revenue			$ 0		$ 0