Pension Benefit Plans (Benefit Payments That Reflect Expected Future Service) (Details) - Pension Benefit Plans $ in Millions	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Expected future benefit payments, next 12 months	$ 230.3
Expected future benefit payments, in year two	232.7
Expected future benefit payments, in year three	232.4
Expected future benefit payments, in year four	234.8
Expected future benefit payments, in year five	233.4
Expected future benefit payments, thereafter	1,152.9
Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Expected future benefit payments, next 12 months	51.9
Expected future benefit payments, in year two	55.8
Expected future benefit payments, in year three	52.9
Expected future benefit payments, in year four	55.5
Expected future benefit payments, in year five	55.2
Expected future benefit payments, thereafter	311.5
United States | Domestic Plan
Defined Benefit Plan Disclosure [Line Items]
Expected future benefit payments, next 12 months	178.4
Expected future benefit payments, in year two	176.9
Expected future benefit payments, in year three	179.5
Expected future benefit payments, in year four	179.3
Expected future benefit payments, in year five	178.2
Expected future benefit payments, thereafter	$ 841.4