Fair Value Measurements - Summary of Assets and Liabilities Recorded at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Assets:
Marketable debt securities	$ 2,179.2	$ 2,433.1
Fair value, measurements, recurring
Assets:
Cash equivalents	2,847.6	1,632.2
Marketable equity securities	791.1	1,048.5
Derivative contracts	63.0	80.9
Plan assets for deferred compensation	32.8	33.4
Total	7,117.9	5,228.1
Liabilities:
Derivative contracts	26.0	10.8
Contingent consideration obligations	0.0	209.1	$ 259.8
Total	26.0	219.9
Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics	798.8
Receivable from Samsung BioLogics	405.4
Fair value, measurements, recurring | Corporate debt securities
Assets:
Marketable debt securities	1,231.6	1,108.2
Fair value, measurements, recurring | Government securities
Assets:
Marketable debt securities	810.3	1,192.7
Fair value, measurements, recurring | Mortgage and other asset backed securities
Assets:
Marketable debt securities	137.3	132.2
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring
Assets:
Cash equivalents	0.0	0.0
Marketable equity securities	791.1	181.7
Derivative contracts	0.0	0.0
Plan assets for deferred compensation	0.0	0.0
Total	791.1	181.7
Liabilities:
Derivative contracts	0.0	0.0
Contingent consideration obligations		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
Receivable from Samsung BioLogics	0.0
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring | Corporate debt securities
Assets:
Marketable debt securities	0.0	0.0
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring | Government securities
Assets:
Marketable debt securities	0.0	0.0
Quoted Prices in Active Markets (Level 1) | Fair value, measurements, recurring | Mortgage and other asset backed securities
Assets:
Marketable debt securities	0.0	0.0
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring
Assets:
Cash equivalents	2,847.6	1,632.2
Marketable equity securities	0.0	866.8
Derivative contracts	63.0	80.9
Plan assets for deferred compensation	32.8	33.4
Total	5,122.6	5,046.4
Liabilities:
Derivative contracts	26.0	10.8
Contingent consideration obligations		0.0
Total	26.0	10.8
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics	0.0
Receivable from Samsung BioLogics	0.0
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring | Corporate debt securities
Assets:
Marketable debt securities	1,231.6	1,108.2
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring | Government securities
Assets:
Marketable debt securities	810.3	1,192.7
Significant Other Observable Inputs (Level 2) | Fair value, measurements, recurring | Mortgage and other asset backed securities
Assets:
Marketable debt securities	137.3	132.2
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	1,204.2	0.0
Liabilities:
Derivative contracts	0.0	0.0
Contingent consideration obligations	0.0	209.1
Total	0.0	209.1
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring | Samsung Bioepis
Assets:
Receivable from Samsung BioLogics	798.8
Receivable from Samsung BioLogics	405.4
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring | Corporate debt securities
Assets:
Marketable debt securities	0.0	0.0
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring | Government securities
Assets:
Marketable debt securities	0.0	0.0
Significant Unobservable Inputs (Level 3) | Fair value, measurements, recurring | Mortgage and other asset backed securities
Assets:
Marketable debt securities	$ 0.0	$ 0.0