Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2018
Income Tax Contingency [Line Items]
Effective tax rate	20.40%		31.10%	27.80%	32.40%
Effective statutory income tax rate				24.50%
Provisional tax expense for the deemed repatriation of undistributed foreign earnings		$ 7.0		$ 7.0
Tax expense for remeasurement of net deferred tax assets				11.6
Unrecognized tax benefit	$ 27.3			$ 27.3
Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Effective statutory income tax rate						24.50%