Pensions - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Sep. 30, 2016
U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer		$ 3.9	$ 5.6
Estimated future employer contributions in current year		1.1
Non-U.S. Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer		0.7	$ 1.0
Estimated future employer contributions in current year		$ 0.2
Scenario, Forecast
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Settlements, Benefit Obligation	$ 7.0