Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 669	$ 1,067	$ 684
Other comprehensive income (loss), net of tax:
Currency translation adjustments	(73)	(23)	(114)
Cash flow hedge adjustments	0	(17)	32
Postretirement benefits adjustments	33	(10)	(30)
Net other comprehensive income (loss)	(40)	(50)	(112)
Comprehensive income	$ 629	$ 1,017	$ 572

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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=51831270

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Amount after tax and reclassification adjustments, of (increase) decrease in accumulated other comprehensive (income) loss related to pension and other postretirement defined benefit plans, attributable to parent entity.

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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