Pension and Other Benefits - Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain		$ (16.1)
Pension Benefits | Domestic Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions by employer	$ 10.0
Pension Benefits | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan estimated total employer contributions in current fiscal year	$ 1.9	1.9
Contributions by employer		1.4
Pension and post retirement benefit plan adjustment
Defined Benefit Plan Disclosure [Line Items]
Curtailment gain		$ 5.1