Income Taxes (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			9 Months Ended		12 Months Ended	15 Months Ended
	Jan. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2019	Mar. 31, 2019
Income Taxes [Abstract]
Effective income tax rate		482.20%		(58.30%)	86.60%	16.00%
US Tax Reforms [Line Items]
Provision (benefit) for income taxes		$ 35.2		$ (0.7)	$ 37.4	$ 1.3
Federal tax rate					31.50%
Valuation Allowance [Line Items]
Unrecognized tax benefits reductions in fiscal 2018			$ (1.8)
Increase in deferred tax assets valuation allowance		1.2
Forecast [Member]
US Tax Reforms [Line Items]
Federal tax rate							21.00%
Foreign Tax Reforms [Member]
Valuation Allowance [Line Items]
Deferred tax asset, valuation allowance		47.4			$ 47.4
Foreign Tax Reforms [Member] | Forecast [Member]
Valuation Allowance [Line Items]
Possible future release of valuation allowance against certain tax assets								$ 3.0
Domestic Tax Jurisdiction [Member]
Valuation Allowance [Line Items]
Deferred tax asset, valuation allowance		7.0			7.0
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Tax benefit from foreign development tax credit		2.2			$ 7.9
U.S Tax Reforms [Member]
US Tax Reforms [Line Items]
Provision (benefit) for income taxes		35.7
Federal tax rate					35.00%
Net reduction of deferred tax assets		(20.7)
Income tax charge for transition tax		$ 15.0
Term of estimated tax liability for transition tax					8 years
U.S Tax Reforms [Member] | Subsequent Event [Member]
US Tax Reforms [Line Items]
Federal tax rate	21.00%
U.S Tax Reforms [Member] | Forecast [Member]
US Tax Reforms [Line Items]
Estimated transition tax liability to be paid in the future							$ 1.0