Additional Balance Sheet & Cash Flow Information - Schedule of Other Current Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Other current liabilities
Milestones payable	$ 32.5	$ 222.5
Contract liabilities	206.8	170.3
Operating lease liabilities	87.1	33.1
Finance lease liabilities	5.2	50.6
Other	31.4	50.7
Total	$ 363.0	$ 527.2