Income Taxes, Unrecognized Tax Benefits and Deferred Tax Asset Valuation Allowances (Details) - USD ($) $ in Millions	3 Months Ended					12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2020	Mar. 31, 2019	Mar. 31, 2018
Income Taxes [Abstract]
Income tax expense related to legal entity restructuring		$ 2.7				$ 2.9
Tax benefit from recognition of tax credits							$ (14.5)
Tax (benefit) from foreign development tax credit						12.4	(5.1)	$ 39.5
Income Taxes [Abstract]
Income tax expense (benefit) related to US Tax Reform			$ 2.2	$ (24.4)			(7.7)
Deferred tax asset, income tax expense (benefit)							2.5
Provisional income tax expense (benefit) related to US Tax Reform								38.0
Change in deferred tax asset valuation allowances	$ 4.1	$ 3.0		$ 1.0	$ (2.0)
Lapse of statute of limitations and settlements						(4.5)
Lapse of statute of limitations						(2.4)	(2.2)	(1.8)
U.S. [Member]
Income Taxes [Abstract]
Change in deferred tax asset valuation allowances						8.4
Foreign Jurisdiction [Member]
Income Taxes [Abstract]
Change in deferred tax asset valuation allowances						(1.3)	(1.0)	(2.8)
Other Tax Jurisdictions [Member]
Income Taxes [Abstract]
Change in deferred tax asset valuation allowances						9.2	$ 4.3
Italy [Member]
Income Taxes [Abstract]
Tax benefit from recognition of tax credits						$ (1.4)
Hungarian Development Tax Credit [Member]
Income Taxes [Abstract]
Tax (benefit) from foreign development tax credit								$ (9.0)