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New Accounting Pronouncements (Narrative) (Details) - ASU No. 2016-09 [Member] - USD ($) $ in Millions | 3 Months Ended
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Mar. 31, 2017 | Mar. 31, 2016
Incentive Stock Award Plans |  |
New Accounting Pronouncements Or Change In Accounting Principle [Line Items] |  |
Provision for income tax expense (benefit) | $ (16.9) |
Reclassification from Operating Activities to Financing Activities [Member] |  |
New Accounting Pronouncements Or Change In Accounting Principle [Line Items] |  |
Shares withheld from employee awards for tax withholding purposes |  | $ 36.0

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- Definition Amount of cash outflow to satisfy an employee's income tax withholding obligation as part of a net-share settlement of a share-based award. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585 + Details
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