Pension and Other Post-Retirement Benefit Plans (Expected Benefit Payments) (Details) $ in Millions	Dec. 31, 2020 USD ($)
Other Post-retirement Benefits
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Expected future benefit payment, next 12 months	$ 0.6
Expected future benefit payment, year two	0.6
Expected future benefit payment, year three	0.6
Expected future benefit payment, year four	0.6
Expected future benefit payment, year five	0.6
Expected future benefit payment, thereafter	2.6
International | Pensions
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Expected future benefit payment, next 12 months	36.6
Expected future benefit payment, year two	30.6
Expected future benefit payment, year three	32.8
Expected future benefit payment, year four	34.8
Expected future benefit payment, year five	34.8
Expected future benefit payment, thereafter	198.3
UNITED STATES | Pensions
Pension and Other Postretirement Benefit Plans Disclosure [Line Items]
Expected future benefit payment, next 12 months	47.6
Expected future benefit payment, year two	32.4
Expected future benefit payment, year three	31.0
Expected future benefit payment, year four	31.7
Expected future benefit payment, year five	31.9
Expected future benefit payment, thereafter	$ 164.3