Held for Sale and Discontinued Operations - Net Change Cash From Discontinued Operations (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash balances at beginning of period	$ 97.1	$ 80.2
Cash balances at end of period	112.2	48.6
Net income tax payment to national governments	0.5	0.0
Discontinued Operations
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Net cash (used for) provided from operations - discontinued operations	0.0	157.0
Net cash provided from investing activities - discontinued operations	0.0	3.0
Net cash used for financing activities - discontinued operations	0.0	(61.9)
Net change in cash during the period	0.0	98.1
Cash balances at beginning of period	0.0	70.5
Cash balances at end of period	0.0	71.3
Interest paid	0.0	0.0
Net income tax payment to national governments	0.0	0.0
Discontinued Operations, Held-for-sale
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash balances at beginning of period	0.0	70.5
Cash balances at end of period	0.0	0.0
Disposal Group, Held-for-sale, Not Discontinued Operations
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Net change in cash held for sale, excluding discontinued operations	0.0	(0.9)
Disposal Group, Held-for-sale or Disposed of by Sale, Not Discontinued Operations
Net Cash Provided by (Used in) Discontinued Operations [Abstract]
Cash sold as part of sale of consolidated subsidiaries	$ 0.0	$ 167.7

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.

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Reduction in cash due to no longer including the former subsidiary's cash in the consolidated entity's cash.

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