Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jan. 31, 2020	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 231	$ 227	$ 699	$ 676
Other comprehensive income (loss), net of tax:
Currency translation adjustments	6	18	3	(21)
Cash flow hedge adjustments	(1)	(8)	1	37
Postretirement benefits adjustments	3	(5)	10	2
Net other comprehensive income (loss)	8	5	14	18
Comprehensive income	$ 239	$ 232	$ 713	$ 694

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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