Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Jan. 27, 2012	Jan. 28, 2011	Jan. 27, 2012	Jan. 28, 2011	Apr. 29, 2011
Income Tax Disclsosure [Abstract]
Tax adjustments	$ (4)
Unrecognized tax benefits that would impact effective tax rate	706		706
Accrued income tax penalties and interest	108		108
Components of earning before income taxes
Earnings before income taxes	1,053	997	3,114	2,766
Provision for income taxes	208	84	587	472
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Effective Income Tax Rate, Continuing Operations	19.75%	8.43%	18.85%	17.06%
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits	780		780		769
Gross unrecognized tax benefits at end of fiscal year	$ 780		$ 780		$ 769

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A ratio calculated by dividing the reported amount of income tax expense attributable to continuing operations for the period by GAAP-basis pretax income from continuing operations.

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- Definition

Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to continuing operations.

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

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Reflects the effects of adjustments of previously recorded tax expense, significant settlements of income tax disputes, and unusual tax positions or infrequent actions taken by the entity, including tax assessment reversal, IRS tax settlement and unusual repatriation of foreign earnings.

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The gross amount of unrecognized tax benefits pertaining to uncertain tax positions taken in tax returns as of the balance sheet date.

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-Glossary Unrecognized Tax Benefit

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This element represents the total of accruals as of the date of the statement of financial position for interest recognized for an underpayment of income taxes computed by applying the applicable statutory rate of interest to the difference between a tax position recognized for financial reporting purposes and the amount previously taken or expected to be taken in a tax return of the entity and the amount of statutory penalties for a tax position claimed or expected to be claimed by the entity, in its tax return, that does not meet the minimum statutory threshold to avoid payment of penalties.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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