Derivatives and Hedging (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jul. 31, 2016	Jul. 31, 2015
Derivative fair values
Foreign currency translation adjustment	$ 1.0	$ (1.7)	$ 2.9
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax		(0.4)	(0.8)
Other comprehensive loss	114.5	134.2	127.3	$ 165.0
Interest Expense
Derivative fair values
Hedge amount to be reclassified	3.1
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Derivative fair values
Foreign currency translation adjustment	3.0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax	(0.6)
AOCI
Derivative fair values
Other comprehensive loss	(17.5)	(20.9)	(21.6)	$ (26.3)
Treasury rate lock | Designated as a hedge
Derivative fair values
Derivative notional amount						$ 300.0
Derivative securities					$ (34.4)
Reclassification out of Accumulated Other Comprehensive Income | AOCI
Derivative fair values
Interest expense	$ 3.0	$ 2.8	$ 2.6