Employee Benefit Plans Expected Benefit Payments (Details) $ in Millions	Dec. 31, 2017 USD ($)
Other Postretirement Benefit Plans
Defined Benefit Plans and Other Postretirement Benefit Plans
Benefit Payments in Year One	$ 12.1
Prescription Drug Subsidy Receipts in Year One	0.2
Net OPEB Payments in Year One	11.9
Benefit Payments in Year Two	11.9
Prescription Drug Subsidy Receipts in Year Two	0.2
Net OPEB Payments in Year Two	11.7
Benefit Payments in Year Three	11.5
Prescription Drug Subsidy Receipts in Year Three	0.2
Net OPEB Payments in Year Three	11.3
Benefit Payments in Year Four	11.2
Prescription Drug Subsidy Receipts in Year Four	0.2
Net OPEB Payments in Year Four	11.0
Benefit Payments in Year Five	10.7
Prescription Drug Subsidy Receipts in Year Five	0.2
Net OPEB Payments in Year Five	10.5
Benefit Payments in Five Fiscal Years Thereafter	46.1
Prescription Drug Subsidy Receipts in Five Fiscal Years Thereafter	0.5
Net OPEB Payments in Five Fiscal Years Thereafter	45.6
Domestic Plan | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Benefit Payments in Year One	74.7
Benefit Payments in Year Two	77.2
Benefit Payments in Year Three	80.7
Benefit Payments in Year Four	84.5
Benefit Payments in Year Five	87.8
Benefit Payments in Five Fiscal Years Thereafter	497.4
Foreign Plan | Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Benefit Payments in Year One	5.2
Benefit Payments in Year Two	5.3
Benefit Payments in Year Three	5.7
Benefit Payments in Year Four	5.9
Benefit Payments in Year Five	6.3
Benefit Payments in Five Fiscal Years Thereafter	$ 36.7