Fair Value Measurements, Valuation Techniques (Details) (Recurring, Level 3, USD $) In Millions, unless otherwise specified	12 Months Ended
Apr. 27, 2012	Apr. 29, 2011
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Balance as of	$ 191	$ 213
Total realized losses and other-than-temporary impairment losses included in earnings	(3)	(6)
Total unrealized gains/(losses) included in other comprehensive income	9	27
Settlements	(25)	(43)
Balance as of	172	191
Corporate Debt Securities
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Balance as of	17	16
Total realized losses and other-than-temporary impairment losses included in earnings	(1)	(2)
Total unrealized gains/(losses) included in other comprehensive income	1	4
Settlements	(7)	(1)
Balance as of	10	17
Auction Rate Securities
Fair Value Inputs
Illiquidity Premium	6.00%
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Balance as of	133	142
Total realized losses and other-than-temporary impairment losses included in earnings	0	0
Total unrealized gains/(losses) included in other comprehensive income	8	20
Settlements	(14)	(29)
Balance as of	127	133
Auction Rate Securities \| Minimum
Fair Value Inputs
Years to Principal Recovery	2 years
Auction Rate Securities \| Maximum
Fair Value Inputs
Years to Principal Recovery	12 years
Auction Rate Securities \| Weighted Average
Fair Value Inputs
Years to Principal Recovery	3 years
Mortgage Backed Securities
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Balance as of	35	39
Total realized losses and other-than-temporary impairment losses included in earnings	(1)	(4)
Total unrealized gains/(losses) included in other comprehensive income	(1)	3
Settlements	(4)	(3)
Balance as of	29	35
Other Asset-backed Securities
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Balance as of	6	16
Total realized losses and other-than-temporary impairment losses included in earnings	(1)	0
Total unrealized gains/(losses) included in other comprehensive income	1	0
Settlements	0	(10)
Balance as of	$ 6	$ 6

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Illiquidity premium used as an input to measure fair value.

+ References

No definition available.

+ Details

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- Definition

Number of years to principal recovery, used as an input to measure fair value.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
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- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in net asset value.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

-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 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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- Definition

This element represents total gains or losses for the period (realized and unrealized), arising from assets measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in other comprehensive income (a separate component of shareholders' equity).

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Settlements that have taken place during the period in relation to assets measured at fair value and categorized within Level 3 of the fair value hierarchy.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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- Definition

This element represents an asset measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c

-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 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6925170&loc=d3e19207-110258

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