Employee Retirement Plans and Postretirement Benefits Changes Recognized Pre-tax (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (income), at the beginning of the period	$ 752.9	$ 838.9
Amortization of prior service (costs) benefit	(0.5)	(0.6)
Amortization of net actuarial (loss) gain	(12.2)	(17.8)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	(1.6)
Settlement	8.3	(10.5)
Current year actuarial loss (gain)	(180.2)	(64.4)
Foreign currency exchange rate change	(4.7)	7.3
Accumulated other comprehensive loss (income), at the end of the period	562.0	752.9
Pension
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (income), at the beginning of the period	800.7	849.3
Amortization of prior service (costs) benefit	(0.5)	(0.7)
Amortization of net actuarial (loss) gain	(12.2)	(17.8)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	0.0
Settlement	5.4	(10.5)
Current year actuarial loss (gain)	(141.5)	(25.8)
Foreign currency exchange rate change	(5.0)	6.2
Accumulated other comprehensive loss (income), at the end of the period	646.9	800.7
OPEB
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive loss (income), at the beginning of the period	(47.8)	(10.4)
Amortization of prior service (costs) benefit	0.0	0.1
Amortization of net actuarial (loss) gain	0.0	0.0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Arising During Period, before Tax	(1.6)
Settlement	2.9	0.0
Current year actuarial loss (gain)	(38.7)	(38.6)
Foreign currency exchange rate change	0.3	1.1
Accumulated other comprehensive loss (income), at the end of the period	$ (84.9)	$ (47.8)