Stock-based Compensation Plans (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 4.7	$ 6.2
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares/Units Awarded (in shares)	64
Restricted Stock Units (RSUs) \| Executive Long-Term Incentive Compensation Plan (the “ELTI Plan”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares/Units Awarded (in shares)	55
Performance Shares \| Executive Long-Term Incentive Compensation Plan (the “ELTI Plan”)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares/Units Awarded (in shares)	53
Continuing Operations
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 4.7	2.8
Discontinued Operations
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation		$ 3.4

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.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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The number of grants made 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).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901

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- Definition

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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