Derivative Financial Instruments and Risk Management - Fair Value of Foreign Currency Derivatives in Balance Sheet (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Derivative Assets	$ 4.8	$ 7.2
Derivative Liabilities	2.6	5.0
Foreign Exchange Contract
Derivative [Line Items]
Derivative Assets	4.4	7.2
Derivative Liabilities	3.0	4.8
Other Current Assets | Foreign Exchange Contract
Derivative [Line Items]
Derivative Assets	4.3	7.2
Other Current Liabilities | Foreign Exchange Contract
Derivative [Line Items]
Derivative Liabilities	3.0	4.8
Other Assets | Foreign Exchange Contract
Derivative [Line Items]
Derivative Assets	0.1	0.0
Other Liabilities | Foreign Exchange Contract
Derivative [Line Items]
Derivative Liabilities	$ 0.0	$ 0.0