Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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Carrying amount as of the balance sheet date of the asset arising from derivative instruments and hedging activities, which are expected to be converted into cash or otherwise disposed of within a year or the normal operating cycle, if longer.

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Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

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Fair Value Measurements (Details) - USD ($) $ in Millions	Oct. 31, 2018	Apr. 30, 2018	Jul. 31, 2017	Apr. 30, 2017
Assets:
Cash and cash equivalents, Carrying Amount	$ 193	$ 239	$ 212	$ 182
Cash and cash equivalents, Fair Value	193	239
Liabilities:
Short-term borrowings, Carrying Amount	258	215
Short-term borrowings, Fair Value	258	215
Long-term debt, Carrying Amount	2,288	2,341
Fair Value, Inputs, Level 2 [Member]
Assets:
Currency derivatives, Fair Value	31	1
Liabilities:
Currency derivatives, Fair Value	6	39
Long-term debt, Fair Value	2,294	2,386
Foreign Exchange Contract [Member]
Assets:
Currency derivatives, Carrying Amount	31	1
Liabilities:
Currency derivatives, Carrying Amount	$ 6	$ 39