Product Sales - Schedule of Net Product Sales (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 3,362.7	$ 2,936.2	$ 9,682.9	$ 8,758.5
Net product sales
Disaggregation of Revenue [Line Items]
Revenues	1,786.1	1,801.4	5,226.2	5,194.4
U.S. | EYLEA
Disaggregation of Revenue [Line Items]
Revenues	1,448.2	1,629.4	4,382.1	4,768.2
U.S. | EYLEA HD
Disaggregation of Revenue [Line Items]
Revenues	42.7	0.0	42.7	0.0
U.S. | Libtayo
Disaggregation of Revenue [Line Items]
Revenues	144.1	94.7	384.0	264.5
U.S. | Praluent
Disaggregation of Revenue [Line Items]
Revenues	40.4	29.7	121.1	94.5
U.S. | Evkeeza
Disaggregation of Revenue [Line Items]
Revenues	19.1	13.6	53.3	33.2
U.S. | Inmazeb
Disaggregation of Revenue [Line Items]
Revenues	3.3	3.0	7.7	3.0
ROW | Libtayo
Disaggregation of Revenue [Line Items]
Revenues	$ 88.3	$ 31.0	$ 235.3	$ 31.0