Benefit Plans (Changes in Projected Benefit Obligation, Fair Value of Plan Assets and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in Benefit Obligation [Roll Forward]
Balance	$ (313.6)
Settlement		$ 139.4
Balance		(313.6)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	188.9
Foreign currency translation	0.0	0.0	$ 0.0
Balance	192.4	188.9
International Pension Plan [Member]
Change in Fair Value of Plan Assets [Roll Forward]
Balance	29.2
Balance	28.8	29.2
Pension Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(246.3)	(398.5)
Service cost	(10.2)	(10.6)	(9.8)
Interest cost	(10.5)	(13.8)	(17.1)
Participants' contributions	(0.6)	(0.6)
Actuarial (loss) gain	(23.4)	7.8
Amendments/transfers in	0.0	(0.8)
Benefits/expenses paid	16.2	14.6
Curtailment	5.2	0.0	0.0
Settlement	0.0	149.7
Foreign currency translation	7.4	4.3
Balance	(262.2)	(246.3)	(398.5)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	188.9	322.3
Actual return on assets	16.8	(6.0)
Employer contribution	6.8	38.0
Participants' contributions	0.6	0.6
Benefits/expenses paid	(16.2)	(14.6)
Settlement	0.0	(149.7)
Foreign currency translation	(4.5)	(1.7)
Balance	192.4	188.9	322.3
Funded status at end of year	(69.8)	(57.4)
Other Retirement Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(10.2)	(10.1)
Service cost	(0.5)	(0.5)	(0.4)
Interest cost	(0.5)	(0.4)	(0.4)
Participants' contributions	(0.5)	(0.6)
Actuarial (loss) gain	0.1	0.8
Amendments/transfers in	(3.0)	0.0
Benefits/expenses paid	0.6	0.6
Curtailment	0.0	0.0
Settlement	0.0	0.0
Foreign currency translation	0.0	0.0
Balance	(8.0)	(10.2)	(10.1)
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	0.5	0.6
Benefits/expenses paid	(0.6)	(0.6)
Settlement	0.0	0.0
Foreign currency translation	0.0	0.0
Balance	0.0	0.0	$ 0.0
Funded status at end of year	$ (8.0)	$ (10.2)