Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Contingencies And Commitments [Line Items]
Defer option specified cost			$ 110.3	$ 110.3
Deferred Finance Costs, Share Lending Arrangement, Issuance Costs			80.9	$ 36.1
Scenario Forecast [Member]
Contingencies And Commitments [Line Items]
Defer option specified cost		$ 110.3
Vertex Pharmaceuticals Incorporated and Certain of its Subsidiaries [Member]
Contingencies And Commitments [Line Items]
Milestone payment receivable			$ 200.0
Cost excluded from license agreement	$ 4.0
Letter of Credit [Member]
Contingencies And Commitments [Line Items]
Letters of credit secured by cash held in restricted depository account	11.5
2015 Collaboration Agreement [Member] | Vertex Pharmaceuticals Incorporated and Certain of its Subsidiaries [Member]
Contingencies And Commitments [Line Items]
Milestone payment receivable	$ 395.0