Stockholders' Equity (Income Tax Benefits Associated With Employee Stock Transactions) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Jan. 27, 2012	Jan. 28, 2011
Stockholders' Equity [Abstract]
Income tax benefits associated with employee stock transactions	$ 74.7	$ 74.9

Reductions in the entity's income taxes that arise when compensation cost (from non-qualified stock options) recognized on the entity's tax return exceeds compensation cost from non-qualified stock options recognized on the income statement. This element increases net cash provided by operating activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A132

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 20

-Section 55

-Paragraph 24

-URI http://asc.fasb.org/extlink&oid=6576910&loc=d3e11374-113907

Name:	us-gaap_TaxBenefitFromStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration