Share-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 35.6	$ 34.7	$ 22.1
Shares available for future grants	7.1
Share-based compensation	$ 35.6	34.7	27.9
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	2.3	2.9	3.3
Intrinsic value of options exercised		0.1	$ 0.6
Tax benefit from equity-based compensation expense	0.2	$ (6.4)
Adjustment to additional paid In capital resulting from income tax effect of share-based compensation	0.3
Unrecognized compensation costs	$ 1.2
Weighted average period for recognition of equity-based compensation expense		1 year 10 months 1 day
Weighted average grant date fair value	$ 3.77	$ 6.82	$ 10.11
Restricted Share Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants	$ 10.50
Share-based compensation expense	$ 23.7	$ 25.6	$ 18.1
Adjustment to additional paid In capital resulting from income tax effect of share-based compensation	3.5
Unrecognized compensation costs	$ 17.5
Weighted average period for recognition of equity-based compensation expense	1 year 11 months 22 days
Award vesting period	3 years
Total fair value of stock that vested during the period	$ 24.3	22.7	26.8
Income tax expense (benefit) related to restricted stock compensation		$ (3.2)	$ 0.5
Weighted average grant date fair value	$ 10.50	$ 20.92	$ 31.40
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants	$ 10.16
Share-based compensation expense	$ 9.4	$ 6.2	$ 0.7
Unrecognized compensation costs	$ 12.3
Weighted average period for recognition of equity-based compensation expense	1 year 10 months 6 days
Weighted average grant date fair value	$ 10.16	$ 21.69	$ 31.57
Restricted Share Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, grants	$ 10.12
Share-based compensation expense	$ 0.2	$ 0.0	$ 0.0
Unrecognized compensation costs	$ 0.1
Weighted average period for recognition of equity-based compensation expense	1 year 3 months 27 days
Continuing Operations [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid	$ 2.8	$ 3.1	1.7
Discontinued Operations [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense			5.8
Discontinued Operations [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid			$ 0.5

Employee Service Share-Based Compensation Tax Expense

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Amount of increase (decrease) in additional paid in capital (APIC) resulting from a tax benefit (deficiency) associated with an share-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

No definition available.

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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method.

+ References

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-Publisher FASB
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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Amount of cash paid related to share-based compensation liabilities.

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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No definition available.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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