Goodwill and Other Intangible Assets (Details) $ in Millions	9 Months Ended
Jan. 31, 2019 USD ($)
Goodwill [Roll Forward]
Balance at April 30, 2018	$ 763
Foreign currency translation adjustment	(9)
Balance at January 31, 2019	754
Indefinite-lived Intangible Assets [Roll Forward]
Balance at April 30, 2018	670
Foreign currency translation adjustment	(19)
Balance at January 31, 2019	$ 651

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

+ References

No definition available.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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