Property and Equipment - Summary of Property and Equipment, Net (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 88	$ 82
Less: Accumulated depreciation and amortization	(41)	(31)
Property and equipment, net	$ 47	51
Minimum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	3 years
Maximum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	10 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 56	54
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	5 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	10 years
Scientific equipment
Property, Plant and Equipment [Line Items]
Useful Life (in years)	5 years
Property and equipment, gross	$ 27	24
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 4	3
Furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	3 years
Furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Life (in years)	5 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1	$ 1