Benefit Plans (Changes in Projected Benefit Obligation, Fair Value of Plan Assets and Funded Status) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Change in Fair Value of Plan Assets [Roll Forward]
Balance	$ 251.0	$ 213.3
Pension Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(319.9)	(283.5)
Service cost	(8.5)	(8.9)	(8.6)
Interest cost	(15.5)	(16.0)	(15.7)
Participants' contributions	0	0
Actuarial (loss) gain	(32.4)	(27.3)
Amendments/transfers in	(0.3)	(0.4)
Benefits/expenses paid	15.3	16.4
Curtailment	0	(0.8)
Foreign currency translation	(1.9)	0.6
Balance	(363.2)	(319.9)	(283.5)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	213.3	212.3
Actual return on assets	32.3	(2.8)
Employer contribution	19.8	20.4
Participants' contributions	0	0
Benefits/expenses paid	(15.3)	(16.4)
Foreign currency translation	0.9	(0.2)
Balance	251.0	213.3	212.3
Funded status at end of year	(112.2)	(106.6)
Other Retirement Benefits [Member]
Change in Benefit Obligation [Roll Forward]
Balance	(21.7)	(18.1)
Service cost	(1.3)	(1.2)	(1.1)
Interest cost	(1.0)	(1.0)	(0.8)
Participants' contributions	(0.5)	(0.3)
Actuarial (loss) gain	(2.1)	(1.4)
Amendments/transfers in	0	0
Benefits/expenses paid	0.6	0.7
Curtailment	0	(0.4)
Foreign currency translation	0	0
Balance	(26.0)	(21.7)	(18.1)
Change in Fair Value of Plan Assets [Roll Forward]
Balance	0	0
Actual return on assets	0	0
Employer contribution	0.1	0.4
Participants' contributions	0.5	0.3
Benefits/expenses paid	(0.6)	(0.7)
Foreign currency translation	0	0
Balance	0	0	0
Funded status at end of year	$ (26.0)	$ (21.7)