Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2018
Effective tax rate	14.90%	(186.70%)
Proceeds and Excess Tax Benefit from Share-based Compensation	$ 3.1
Federal Corporate tax rate	21.00%	35.00%			21.00%
Deferred Tax Remeasurement, Amount				$ (93.8)
Blended Corporate Tax rate	24.50%
Federal statutory income tax rate			21.00%
Global intangible low-taxed income- foreign tax deduction	50.00%
Discrete net tax benefit- Tax Act	$ 64.3	$ 2.9		70.9
Income Tax Expense (Benefit)	7.4	$ (57.5)
Transition tax obligation, amount	21.9			$ 22.9
Reduction to Transition Tax Liability	1.0
Reduction in Taxes [Member]
Transition tax obligation, amount	$ 1.0