Equity Investments (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Equity Method Investments [Line Items]
Distributions from equity interest	$ 69.1	$ 86.9	$ 64.2
Equity method investment, sales reported on consolidated financial statements	31.2	29.8	29.9
Equity earnings in joint venture	$ 67.0	73.1	66.1
Customer Relationships [Member]
Schedule of Equity Method Investments [Line Items]
Amortizing intangible assets, Estimated Useful Life	20 years
Developed Technology [Member]
Schedule of Equity Method Investments [Line Items]
Amortizing intangible assets, Estimated Useful Life	15 years
WAVE [Member]
Schedule of Equity Method Investments [Line Items]
Equity interest percentage	50.00%
Distributions from equity interest	$ 69.1	86.9	64.2
Equity method investment, difference between carrying amount and underlying equity	161.0	166.6
WAVE [Member] | European and Pacific Rim Businesses [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings in joint venture	$ 1.7	$ 2.8	$ 2.6
WAVE [Member] | Customer Relationships [Member]
Schedule of Equity Method Investments [Line Items]
Amortizing intangible assets, Estimated Useful Life	20 years
WAVE [Member] | Developed Technology [Member]
Schedule of Equity Method Investments [Line Items]
Amortizing intangible assets, Estimated Useful Life	15 years
WAVE [Member] | Trademarks [Member]
Schedule of Equity Method Investments [Line Items]
Non-amortizing intangible assets, estimated useful life	indefinite