Financial Instruments (Fair Value Measurement of Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Level 1 [Member] | Foreign Currency Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets (liabilities), net	$ (0.8)	$ 1.3
Level 2 [Member] | Natural Gas Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets (liabilities), net	(0.6)	1.0
Level 2 [Member] | Interest Rate Swap Contracts [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets (liabilities), net	$ 8.9	$ 6.9