Benefit Plans (Changes in Projected Benefit Obligation, Fair Value of Plan Assets and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in Benefit Obligation [Roll Forward]
Service cost	$ (10.8)	$ (10.4)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	239.5
Balance	214.5	239.5
Pension Plan [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(288.0)	(262.2)
Service cost	(10.8)	(10.4)	$ (10.2)
Interest cost	(9.4)	(9.8)	(10.5)
Participants’ contributions	(0.6)	(0.7)
Actuarial (loss) gain	20.4	(11.8)
Amendments/transfers in	(0.3)	0.0
Benefits/expenses paid	18.0	14.2
Foreign currency translation	3.7	(7.3)
Balance	(267.0)	(288.0)	(262.2)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	239.5	192.4
Actual return on assets	(8.3)	34.4
Employer contribution	(2.7)	(23.2)
Participants’ contributions	0.6	0.7
Benefits/expenses paid	(18.0)	(14.2)
Foreign currency translation	(2.0)	3.0
Balance	214.5	239.5	192.4
Funded status at end of year	(52.5)	(48.5)
Other Postretirement Benefits Plan [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(7.1)	(8.0)
Service cost	0.0	0.0	(0.5)
Interest cost	(0.2)	(0.3)	(0.5)
Participants’ contributions	(0.6)	(0.5)
Actuarial (loss) gain	1.4	1.2
Amendments/transfers in	0.0	0.0
Benefits/expenses paid	0.5	0.5
Foreign currency translation	0.0	0.0
Balance	(6.0)	(7.1)	(8.0)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	0.0	0.0
Actual return on assets	0.0	0.0
Employer contribution	(0.1)	0.0
Participants’ contributions	0.6	0.5
Benefits/expenses paid	(0.5)	(0.5)
Foreign currency translation	0.0	0.0
Balance	0.0	0.0	$ 0.0
Funded status at end of year	$ (6.0)	$ (7.1)