New Accounting Pronouncements (Narrative) (Details) - ASU No. 2016-09 [Member] - USD ($) $ in Millions	3 Months Ended
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

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.

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

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