Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended	6 Months Ended
Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016
Numerator:
Net income attributable to ordinary shareholders	$ 2,017	$ 1,115	$ 3,033	$ 2,044
Denominator:
Basic weighted average shares outstanding (shares)	1,355.1	1,380.0	1,358.5	1,386.5
Effect of dilutive securities:
Employee stock options (shares)	7.7	9.3	8.5	9.9
Employee restricted stock units (shares)	3.0	3.2	3.5	3.6
Other (shares)	0.0	0.0	0.3	0.2
Diluted weighted average shares outstanding (shares)	1,365.8	1,392.5	1,370.8	1,400.2
Basic earnings per share (usd per share)	$ 1.49	$ 0.81	$ 2.23	$ 1.47
Diluted earnings per share (usd per share)	$ 1.48	$ 0.80	$ 2.21	$ 1.46
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (shares)	12.0	5.0	8.0	4.0

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Incremental Common Shares Attributable to Dilutive Effect of Other Shares

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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