Fair Value Measurements - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended
Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Financial Instruments Measured at Fair Value on a Recurring Basis
Cash and cash equivalents and short-term investments		$ 2,200.0	$ 2,300.0
Restricted cash and cash equivalents and restricted short-term investments		1,100.0	1,200.0
Payments to acquire equity method investments	$ 10.0
Cash and Cash Equivalents and Short-Term Investments
Financial Instruments Measured at Fair Value on a Recurring Basis
Cash		44.2	133.6
Cash and Cash Equivalents and Short-Term Investments \| Fair Value Measurements on Nonrecurring Basis
Financial Instruments Measured at Fair Value on a Recurring Basis
Cash		44.2	133.6
Money market deposits		180.0	174.3
Term deposits		640.0	601.0
Restricted Cash and Cash Equivalents and Restricted Investments
Financial Instruments Measured at Fair Value on a Recurring Basis
Restricted cash		57.0	53.8
Restricted Cash and Cash Equivalents and Restricted Investments \| Fair Value Measurements on Nonrecurring Basis
Financial Instruments Measured at Fair Value on a Recurring Basis
Money market deposits			0.2
Term deposits		6.5	6.5
Restricted cash		$ 57.0	$ 53.8

Cash And Cash Equivalents And Short-Term Investments

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Restricted Cash And Cash Equivalents And Restricted Short-Term Investments

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Amount 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. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Amount of deposits in accounts that offer many of the same services as checking accounts although transactions may be somewhat more limited, share some of the characteristics of a money market fund and are insured by the Federal government, also known as money market accounts.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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For banks and other depository institutions (including Federal Reserve Banks, if applicable): Interest-bearing deposits in other financial institutions for relatively short periods of time including, for example, certificates of deposits, which are presented separately from cash on the balance sheet.

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The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence.

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Amount of cash restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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