Cash and Cash Equivalents - Schedule of Cash and Cash Equivalents (Detail) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash and cash equivalents [abstract]
Cash at bank and on hand	$ 399.7	$ 479.0
Total cash and cash equivalents	$ 399.7	$ 479.0	$ 526.7	$ 440.0

The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-IssueDate 2018-01-01
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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