Research Collaboration and License Agreements - Summary of Contract Balances (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Accounts receivable related to collaborations
Beginning balance	$ 5.7	$ 0.0
Additions	20.4	8.7
Payments received	(5.8)	(1.4)
Ending balance	20.3	7.3
Accounts payable related to collaborations
Beginning balance	5.4	13.1
Additions	39.3	43.5
Payments made	(34.9)	(42.3)
Ending balance	9.8	14.3
Contract assets: Collaboration contract asset
Beginning balance	7.8	9.4
Additions	0.0	3.0
Amortization	(4.1)	(3.6)
Ending balance	3.7	8.8
Contract liabilities: Deferred revenue
Beginning balance	448.2	549.2
Additions to collaboration agreements	0.0	130.0
Revenue recognized from balances held at the beginning of the period	(233.1)	(82.0)
Revenue recognized from new collaborations	0.0	(93.5)
Ending balance	$ 215.1	$ 503.7