Income Taxes (Details Textual) - USD ($) $ in Millions	4 Months Ended	8 Months Ended	12 Months Ended
	Apr. 30, 2018	Dec. 31, 2017	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2017
Tax Credit Carryforward [Line Items]
Income tax expense (benefit)			$ 247.2	$ 187.2	$ (477.6)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	35.00%	21.00%	21.00%	30.40%
Net impact of adjustments			$ (765.8)
Valuation allowance on operating loss carryforward			26.2
Foreign Earnings Repatriated			39.7
Undistributed earnings of foreign subsidiaries on which deferred income taxes not provided			29.7
Company's unrecognized tax benefits	$ 32.3		13.1	$ 15.0	$ 32.3	$ 40.4
Unrecognized tax benefits that would affect the effective tax rate	21.5		10.5	12.0	21.5
Tax-related net interest and penalties	$ 4.0		1.9	3.3	4.0
Interest Charged (Credited) To Earnings			$ (0.1)	$ (0.8)	$ 0.1
Time period over which it is reasonably possible that the Company could decrease its unrecognized tax benefits			12 months
Amount unrecognized tax benefit could decrease in next 12 months			$ 2.6