Income Taxes (Schedule of Income from U.S. and Foreign Operations) (Details) - USD ($) $ in Millions	12 Months Ended
Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2016
Domestic and Foreign components of our Income before Income taxes
United States	$ 747	$ 806	$ 1,184
Foreign	230	127	305
Income before income taxes	$ 977	$ 933	$ 1,489

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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