Income Taxes - Additional Information (Detail) £ in Millions	12 Months Ended
	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2024 GBP (£)
Changes in valuation allowance	$ 39,000,000	$ 21,600,000
Unrecognized tax benefits	0	0
Unrecognized tax benefits recognized in comprehensive income (loss)	0
Accrued penalties or interest related to uncertain tax positions	0	0
Capitalized research and development expenses net section 174	113,900,000	$ 57,200,000
U.S. Federal [Member]
Operating loss carry forwards	$ 369,500,000
Operating loss carry forwards, expiration range start dates	2024
Operating loss carry forwards, expiration range end dates	2039
Tax years that remain subject to examination	2014 2015 2016 2017 2018 2019 2020 2021 2022
State [Member]
Operating loss carry forwards	$ 326,000,000
Operating loss carry forwards, expiration range start dates	2033
Operating loss carry forwards, expiration range end dates	2040
United Kingdom Tax Authority [Member]
Operating loss carry forwards	$ 25,300,000		£ 20.9
Tax years that remain subject to examination	2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021
Expire Year Between 2023 and 2039 | U.S. Federal [Member]
Operating loss carry forwards	$ 151,800,000
Federal and State Research and Development Tax Credit Carryforward [Member]
Research and development tax credit carry forwards	$ 10,700,000
Federal And State Tax [Member]
Research and development tax credit carry forwards expiration begin date	2024
Research and development tax credit carry forwards expiration end date	2040
Icon Bioscience Inc [Member] | U.S. Federal [Member]
Operating loss carry forwards	$ 49,300,000