Segment Information - Schedule of Revenues by Product (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenue from External Customer [Line Items]
Total product revenues, net	$ 2,964.7	$ 2,645.6	$ 5,734.9	$ 5,336.2
Product revenues, net
Revenue from External Customer [Line Items]
Total product revenues, net	2,944.0	2,645.6	5,704.2	5,336.2
TRIKAFTA/KAFTRIO
Revenue from External Customer [Line Items]
Total product revenues, net	2,551.1	2,449.2	5,086.6	4,932.8
ALYFTREK
Revenue from External Customer [Line Items]
Total product revenues, net	156.8	0.0	210.7	0.0
Other product revenues
Revenue from External Customer [Line Items]
Total product revenues, net	$ 236.1	$ 196.4	$ 406.9	$ 403.4