Derivatives and Hedging (Details) - Derivative Gains And Losses That Have Been Recognized In Condensed Consolidated Statements Of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	$ 7.1	$ 7.9	$ 8.6
Interest expense
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	7.9	7.6	8.5
Other income, net
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments, gain (loss) recognized in income, net	$ (0.8)	$ 0.3	$ 0.1