Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	$ 14,967.4	$ 12,533.9
Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,767.3	6,398.0
U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,998.6	4,833.4
Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	66.9	57.2
Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	557.6	636.8
Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	403.1	521.4
Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	173.9	87.1
Measured on a recurring basis
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	934.8	928.1
Total assets	17,210.4	14,439.4
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	36.7	43.7
Measured on a recurring basis \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	1,232.1	864.5
Measured on a recurring basis \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	76.1	112.9
Measured on a recurring basis \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,767.3	6,398.0
Measured on a recurring basis \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,998.6	4,833.4
Measured on a recurring basis \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	66.9	57.2
Measured on a recurring basis \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	557.6	636.8
Measured on a recurring basis \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	403.1	521.4
Measured on a recurring basis \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	173.9	87.1
Measured on a recurring basis \| Level 1
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	517.3	6.4
Total assets	1,825.5	983.8
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	0.0	0.0
Measured on a recurring basis \| Level 1 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	1,232.1	864.5
Measured on a recurring basis \| Level 1 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	76.1	112.9
Measured on a recurring basis \| Level 1 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 1 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 1 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 1 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 1 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 1 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 2
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	417.5	921.7
Total assets	15,384.9	13,455.6
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	0.0	0.0
Measured on a recurring basis \| Level 2 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0.0	0.0
Measured on a recurring basis \| Level 2 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0.0	0.0
Measured on a recurring basis \| Level 2 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	7,767.3	6,398.0
Measured on a recurring basis \| Level 2 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	5,998.6	4,833.4
Measured on a recurring basis \| Level 2 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	66.9	57.2
Measured on a recurring basis \| Level 2 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	557.6	636.8
Measured on a recurring basis \| Level 2 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	403.1	521.4
Measured on a recurring basis \| Level 2 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	173.9	87.1
Measured on a recurring basis \| Level 3
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	0.0	0.0
Total assets	0.0	0.0
Liabilities, Fair Value Disclosure [Abstract]
Contingent consideration	36.7	43.7
Measured on a recurring basis \| Level 3 \| Unrestricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Restricted
Assets, Fair Value Disclosure [Abstract]
Equity securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Corporate bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| U.S. government and government agency obligations
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Sovereign bonds
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Commercial paper
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Certificates of deposit
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	0.0	0.0
Measured on a recurring basis \| Level 3 \| Asset-backed securities
Assets, Fair Value Disclosure [Abstract]
Available-for-sale debt securities	$ 0.0	$ 0.0

Fair value portion of asset recognized for present right to economic benefit.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of liability recognized arising from contingent consideration in a business combination.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as noncurrent.

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