Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Jul. 31, 2018	Jul. 31, 2017	Apr. 30, 2018
Effective income tax rate [Abstract]
Effective tax rate as reported	22.80%	(51.50%)
Impact of restructuring and impairment charges	(0.10%)	69.60%
Effective tax rate excluding the impact of restructuring and impairment charges	22.70%	18.10%
The Tax Act [Abstract]
Provisional estimated net tax benefit related to the Tax Act			$ (25.1)
Federal statutory tax rate	21.00%

No definition available.

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Percentage of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to increase (decrease) in income tax rate and transition tax on accumulated earnings of controlled foreign corporation deemed repatriated pursuant to Tax Cuts and Jobs Act of 2017.

+ References

No definition available.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations, excluding the impact of non-recurring items from the Tax Act and the foreign court decision and tax rate change.

+ References

No definition available.

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Amount of reasonable estimate for income tax expense (benefit) from effect of Tax Cuts and Jobs Act of 2017 for which accounting for tax effect is incomplete.

+ References

No definition available.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

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-Name Accounting Standards Codification
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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