Benefit Plans (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net periodic benefit cost:
Settlement effects	$ 50.4	$ 0.0	$ 0.0
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Foreign currency translation	0.0	0.0	0.0
Pension Benefits [Member]
Net periodic benefit cost:
Service cost	10.6	9.8	9.7
Interest cost	13.8	17.1	14.8
Expected return on assets	(19.5)	(19.3)	(17.3)
Amortization of prior service (credit) cost	(1.3)	(1.3)	(1.3)
Amortization of transition obligation	0.1	0.1	0.1
Amortization of actuarial loss (gain)	5.9	4.7	9.2
Settlement effects	50.4	0.0	0.0
Net periodic benefit cost	60.0	11.1	15.2
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Net loss (gain) arising during period	17.7	31.5	(36.1)
Prior service credit arising during period	(0.7)	0.0	0.0
Amortization of prior service credit	1.3	1.3	1.3
Amortization of transition obligation	(0.1)	(0.1)	(0.1)
Amortization of actuarial (loss) gain	(5.9)	(4.7)	(9.2)
Settlement effects	50.4	0.0	0.0
Foreign currency exchange rate effects on the above items	(1.6)	(2.1)	0.6
Foreign currency translation	(1.7)	(2.2)
Total recognized in other comprehensive income	(39.7)	25.9	(43.5)
Total recognized in net periodic benefit cost and other comprehensive income	20.3	37.0	(28.3)
U.S. Pension Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	57.4	8.1	11.9
International Pension Plan [Member]
Net periodic benefit cost:
Net periodic benefit cost	2.6	3.0	3.3
Other Retirement Benefits [Member]
Net periodic benefit cost:
Service cost	0.5	0.4	1.1
Interest cost	0.4	0.4	0.6
Expected return on assets	0.0	0.0	0.0
Amortization of prior service (credit) cost	0.0	0.0	0.0
Amortization of transition obligation	0.0	0.0	0.0
Amortization of actuarial loss (gain)	(1.4)	(1.6)	(0.7)
Settlement effects	0.0	0.0	0.0
Net periodic benefit cost	(0.5)	(0.8)	1.0
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Net loss (gain) arising during period	(0.8)	0.1	(18.5)
Prior service credit arising during period	0.0	0.0	0.0
Amortization of prior service credit	0.0	0.0	0.0
Amortization of transition obligation	0.0	0.0	0.0
Amortization of actuarial (loss) gain	1.4	1.6	0.7
Settlement effects	0.0	0.0	0.0
Foreign currency translation	0.0	0.0
Total recognized in other comprehensive income	0.6	1.7	(17.8)
Total recognized in net periodic benefit cost and other comprehensive income	0.1	0.9	(16.8)
U.S. Defined Benefit Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	(0.5)	(0.8)	1.0
International Defined Benefit Plans [Member]
Net periodic benefit cost:
Net periodic benefit cost	$ 0.0	$ 0.0	$ 0.0