Benefit Plans (Components of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension Benefits [Member]
Net periodic benefit cost:
Service cost	$ 9.8	$ 9.7	$ 8.5
Interest cost	17.1	14.8	15.5
Expected return on assets	(19.3)	(17.3)	(16.4)
Amortization of prior service (credit) cost	(1.3)	(1.3)	(1.4)
Amortization of transition obligation	0.1	0.1	0.1
Amortization of actuarial loss (gain)	4.7	9.2	8.5
Net periodic benefit cost	11.1	15.2	14.8
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Net loss (gain) arising during period	31.5	(36.1)	16.5
Amortization of prior service credit (cost)	1.3	1.3	1.4
Amortization of transition obligation	(0.1)	(0.1)	(0.1)
Amortization of actuarial (loss) gain	(4.7)	(9.2)	(8.5)
Foreign currency exchange rate effects on the above items	(2.1)	0.6	0.8
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	(2.2)	0.8
Total recognized in other comprehensive income	25.9	(43.5)	10.1
Total recognized in net periodic benefit cost and other comprehensive income	37.0	(28.3)	24.9
U.S. Pension Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	8.1	11.9	12.0
International Pension Plan [Member]
Net periodic benefit cost:
Net periodic benefit cost	3.0	3.3	2.8
Other Retirement Benefits [Member]
Net periodic benefit cost:
Service cost	0.4	1.1	1.3
Interest cost	0.4	0.6	1.0
Expected return on assets	0	0	0
Amortization of prior service (credit) cost	0	0	0.1
Amortization of transition obligation	0	0	0
Amortization of actuarial loss (gain)	(1.6)	(0.7)	0
Net periodic benefit cost	(0.8)	1.0	2.4
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Net loss (gain) arising during period	0.1	(18.5)	2.1
Amortization of prior service credit (cost)	0	0	(0.1)
Amortization of transition obligation	0	0	0
Amortization of actuarial (loss) gain	1.6	0.7	0
Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets	0	0
Total recognized in other comprehensive income	1.7	(17.8)	2.0
Total recognized in net periodic benefit cost and other comprehensive income	0.9	(16.8)	4.4
U.S. Defined Benefit Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	(0.8)	1.0	2.4
International Defined Benefit Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	$ 0	$ 0	$ 0