Benefit Plans Benefit Plans - Future Benefit Payments (Details) $ in Millions	Dec. 31, 2017 USD ($)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Amount of net prior service credit	$ 0.0
Amount of net loss	0.0
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
2018, gross	1.1
2019, gross	1.0
2020, gross	1.0
2021, gross	0.9
2022, gross	0.9
2023-2027, gross	3.7
2018, net	1.0
2019, net	0.9
2020, net	0.9
2021, net	0.9
2022, net	0.8
2023-2027, net	3.4
U.S. Plans | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Amount of net prior service credit	0.0
Amount of net loss	6.6
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
2018	27.9
2019	28.5
2020	29.1
2021	29.8
2022	30.3
2023-2027	157.6
Foreign Plan [Member] | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Amount of net prior service credit	(0.1)
Amount of net loss	(0.6)
Defined Benefit Plan, Expected Amortization, Next Fiscal Year [Abstract]
2018	28.7
2019	26.6
2020	25.8
2021	27.3
2022	24.6
2023-2027	$ 130.4