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Fair Value Measurements - Schedule of Assets Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Millions | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | $ 10,051.3 | $ 10,018.2
Corporate bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 6,592.2 | 6,684.4
U.S. government and government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 2,903.4 | 2,939.4
Sovereign bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 70.4 | 64.1
Commercial paper |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 279.1 | 121.1
Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 153.7 | 182.0
Asset-backed securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 52.5 | 27.2
Measured on a recurring basis |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash equivalents | 1,422.7 | 1,662.8
Assets, Fair Value Disclosure, Total | 12,532.7 | 12,891.0
Measured on a recurring basis | Unrestricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 20.7 | 24.6
Measured on a recurring basis | Restricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 1,038.0 | 1,185.4
Measured on a recurring basis | Corporate bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 6,592.2 | 6,684.4
Measured on a recurring basis | U.S. government and government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 2,903.4 | 2,939.4
Measured on a recurring basis | Sovereign bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 70.4 | 64.1
Measured on a recurring basis | Commercial paper |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 279.1 | 121.1
Measured on a recurring basis | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 153.7 | 182.0
Measured on a recurring basis | Asset-backed securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 52.5 | 27.2
Measured on a recurring basis | Level 1 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash equivalents | 154.1 | 88.3
Assets, Fair Value Disclosure, Total | 1,203.1 | 1,298.3
Measured on a recurring basis | Level 1 | Unrestricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 20.7 | 24.6
Measured on a recurring basis | Level 1 | Restricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 1,028.3 | 1,185.4
Measured on a recurring basis | Level 1 | Corporate bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 1 | U.S. government and government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 1 | Sovereign bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 1 | Commercial paper |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 1 | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 1 | Asset-backed securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 0.0 | 0.0
Measured on a recurring basis | Level 2 |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Cash equivalents | 1,268.6 | 1,574.5
Assets, Fair Value Disclosure, Total | 11,329.6 | 11,592.7
Measured on a recurring basis | Level 2 | Unrestricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 0.0 | 0.0
Measured on a recurring basis | Level 2 | Restricted |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Equity securities | 9.7 | 0.0
Measured on a recurring basis | Level 2 | Corporate bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 6,592.2 | 6,684.4
Measured on a recurring basis | Level 2 | U.S. government and government agency obligations |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 2,903.4 | 2,939.4
Measured on a recurring basis | Level 2 | Sovereign bonds |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 70.4 | 64.1
Measured on a recurring basis | Level 2 | Commercial paper |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 279.1 | 121.1
Measured on a recurring basis | Level 2 | Certificates of deposit |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | 153.7 | 182.0
Measured on a recurring basis | Level 2 | Asset-backed securities |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |
Available-for-sale debt securities | $ 52.5 | $ 27.2

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- Definition 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. + References No definition available. + Details
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