Significant Accounting Policies - Summary of Reconciliation of Cash, Cash Equivalents and Restricted Cash for Balance Sheets and Cash Flows (Detail) - USD ($) $ in Millions |
Jun. 30, 2018 |
Dec. 31, 2017 |
Jun. 30, 2017 |
Dec. 31, 2016 |
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| Cash, Cash Equivalents and Restricted Cash [Line Items] | ||||
| Cash and cash equivalents | $ 839.4 | $ 1,278.8 | ||
| Total cash, cash equivalents, and restricted cash shown in the statement of cash flows | 855.1 | 1,295.5 | $ 1,639.4 | $ 857.0 |
| Prepaid expenses and other current assets [Member] | ||||
| Cash, Cash Equivalents and Restricted Cash [Line Items] | ||||
| Restricted cash | 3.5 | 4.0 | ||
| Other Assets [Member] | ||||
| Cash, Cash Equivalents and Restricted Cash [Line Items] | ||||
| Restricted cash | $ 12.2 | $ 12.7 |
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- Definition Cash, cash equivalents and restricted cash. No definition available.
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- Definition 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. 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. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of cash and cash equivalents, and cash and cash equivalents restricted to withdrawal or usage. Excludes amount for disposal group and discontinued operations. 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. Cash equivalents include, but are not limited to, 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition Amount of cash restricted as to withdrawal or usage. 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. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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