Stock-Based Compensation (Intrinsic Value and Tax Deductions of Stock Appreciation Rights) (Details) - Stock Appreciation Rights [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Instrinsic value of stock appreciation rights exercised	$ 27.3	$ 27.3	$ 16.7
Realized tax benefits from tax deductions	$ 10.4	$ 10.4	$ 6.4

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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