Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2018	Oct. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 249	$ 239	$ 449	$ 417
Other comprehensive income (loss), net of tax:
Currency translation adjustments	(27)	(25)	(39)	9
Cash flow hedge adjustments	22	7	45	(16)
Postretirement benefits adjustments	4	3	7	6
Net other comprehensive income (loss)	(1)	(15)	13	(1)
Comprehensive income	$ 248	$ 224	$ 462	$ 416

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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