Derivatives and Hedging Activities - Offsetting Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Offsetting Liabilities [Line Items]
Gross position	$ (5.7)	$ (16.9)
Other Current Liabilities
Offsetting Liabilities [Line Items]
Gross position	(5.7)	(11.6)
Reclassified to held for sale	0.0	2.3
Impact of master netting agreements	0.4	0.2
Net amounts recognized on the Consolidated Balance Sheet	(5.3)	(9.1)
Other Noncurrent Liabilities
Offsetting Liabilities [Line Items]
Gross position	0.0	(5.3)
Reclassified to held for sale	0.0	0.0
Impact of master netting agreements	0.0	0.0
Net amounts recognized on the Consolidated Balance Sheet	$ 0.0	$ (5.3)