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Related Party Transactions - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 29, 2022	Jul. 31, 2022	Jun. 30, 2023	Jun. 30, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Feb. 29, 2016
Related Party Transaction [Line Items]
Deferred income - related party					$ 7,730	$ 0
Common stock, shares issued	8,738,243
Common stock, par value	$ 3.15				$ 0.001	$ 0.001
Proceeds from issuance of common stock	$ 27,525				$ 0	$ 96,721	$ 0
Nestle Health Science [Member]
Related Party Transaction [Line Items]
Collaboration revenue - related party					(650)	3,014	10,446
Deferred revenue					95,364	94,713		$ 120,000
Due from related party					0	0
Nestle Health Science [Member] \| 2021 License Agreement [Member]
Related Party Transaction [Line Items]
Collaboration revenue - related party					126,975	4,114	133,411
Deferred revenue					0	1,976
Payments under agreements with related party					37,387	0
Payment for collaboration receivable					31,243	0
Due from related party					8,674	0
Nestle Health Science [Member] \| 2021 License Agreement [Member] \| Accrued Expenses and Other Current Liabilities [Member]
Related Party Transaction [Line Items]
Transaction price allocated under collaborative arrangement					$ 28,053	34,770
Flagship Pioneering [Member]
Related Party Transaction [Line Items]
Proceeds from issuance of common stock	$ 27,525
Flagship Pioneering [Member] \| Sublease Agreement [Member]
Related Party Transaction [Line Items]
Lessee, term of operating sublease, description					The term of the sublease agreement commenced in July 2019 and ended in November 2021
Sub lease commencement date					2019-07
Flagship Pioneering [Member] \| Sublease Agreement [Member] \| Other Income [Member]
Related Party Transaction [Line Items]
Sublease income					$ 0	$ 0	$ 1,575
TPC, Inc. [Member] \| Other Noncurrent Assets [Member]
Related Party Transaction [Line Items]
Option Payment1		$ 833
TPC, Inc. [Member] \| Research and Development Expense [Member]
Related Party Transaction [Line Items]
Option Payment1			$ 833	$ 833