Fair Value Measurement (Carrying value and estimated fair value) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value
Assets
Cash and cash equivalents	$ 560.0	$ 841.6
Carrying Value
Assets
Cash and cash equivalents	560.0	841.6
Term Loans \| Fair Value
Liabilities
Debt	1,300.5	2,115.1
Term Loans \| Carrying Value
Liabilities
Debt	2,595.9	2,662.7
Secured Debt \| Fair Value
Liabilities
Debt	269.7	383.4
Secured Debt \| Carrying Value
Liabilities
Debt	$ 282.3	$ 396.4

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.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant