Fair Value Measurements - Summary of Assets and Liabilities Recorded at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Jun. 30, 2022	Apr. 30, 2022	Jun. 30, 2018	Feb. 29, 2012
Assets:
Derivative Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Current
Other current liabilities:
Contingent consideration obligations	$ 291.2
Other non-current liabilities:
Contingent consideration obligations	221.6
Samsung Bioepis
Other non-current liabilities:
Ownership percentage			49.90%	49.90%	49.90%	15.00%
Fair value, measurements, recurring
Assets:
Cash equivalents	1,664.9	$ 610.7
Marketable equity securities	179.7	416.8
Derivative contracts	62.5	11.9
Plan assets for deferred compensation	42.8	37.5
Total	1,949.9	1,506.9
Other current liabilities:
Derivative contracts	11.7
Contingent consideration obligations	291.2
Other non-current liabilities:
Contingent consideration obligations	221.6
Derivative contracts		31.6
Total	524.5	31.6
Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics		430.0
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring
Assets:
Cash equivalents	0.0	0.0
Marketable equity securities	179.7	416.8
Derivative contracts	0.0	0.0
Plan assets for deferred compensation	0.0	0.0
Total	179.7	416.8
Other current liabilities:
Derivative contracts	0.0
Contingent consideration obligations	0.0
Other non-current liabilities:
Contingent consideration obligations	0.0
Derivative contracts		0.0
Total	0.0	0.0
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics		0.0
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets:
Cash equivalents	1,664.9	610.7
Marketable equity securities	0.0	0.0
Derivative contracts	62.5	11.9
Plan assets for deferred compensation	42.8	37.5
Total	1,770.2	660.1
Other current liabilities:
Derivative contracts	11.7
Contingent consideration obligations	0.0
Other non-current liabilities:
Contingent consideration obligations	0.0
Derivative contracts		31.6
Total	11.7	31.6
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics		0.0
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring
Assets:
Cash equivalents	0.0	0.0
Marketable equity securities	0.0	0.0
Derivative contracts	0.0	0.0
Plan assets for deferred compensation	0.0	0.0
Total	0.0	430.0
Other current liabilities:
Derivative contracts	0.0
Contingent consideration obligations	291.2
Other non-current liabilities:
Contingent consideration obligations	221.6
Derivative contracts		0.0
Total	$ 512.8	0.0
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics		$ 430.0