v2.4.1.9

Fair Value of Financial Assets and Liabilities (Details) (USD $)

Jan. 25, 2015

Jan. 26, 2014

Financial assets and liabilities measured at fair value

Convertible Debt, Fair Value Disclosures

$ 1,679,600,000us-gaap_ConvertibleDebtFairValueDisclosures

$ 1,528,400,000us-gaap_ConvertibleDebtFairValueDisclosures

Debt Instrument, Face Amount

1,500,000,000us-gaap_DebtInstrumentFaceAmount

1,500,000,000us-gaap_DebtInstrumentFaceAmount

Estimated Fair Value

4,421,395,000us-gaap_AvailableForSaleSecurities

4,092,648,000us-gaap_AvailableForSaleSecurities

US Government Agencies Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

750,320,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember

1,013,327,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember

Cash and Cash Equivalents, Fair Value Disclosure

15,000,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember

Marketable Securities

735,300,000us-gaap_MarketableSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember

Corporate Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

2,186,311,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember

1,763,725,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember

Cash and Cash Equivalents, Fair Value Disclosure

147,200,000us-gaap_CashAndCashEquivalentsFairValueDisclosure
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember

Marketable Securities

2,000,000,000us-gaap_MarketableSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember

Mortgage backed securities issued by United Sates government-sponsored enterprises

Financial assets and liabilities measured at fair value

Estimated Fair Value

278,105,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember

188,706,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember

Money Market Funds

Financial assets and liabilities measured at fair value

Estimated Fair Value

132,495,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember

307,865,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember

US Treasury Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

536,364,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USTreasurySecuritiesMember

496,453,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USTreasurySecuritiesMember

Asset-backed Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

452,884,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AssetBackedSecuritiesMember

257,717,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AssetBackedSecuritiesMember

Fair Value, Inputs, Level 1 [Member]

Financial assets and liabilities measured at fair value

Estimated Fair Value

132,495,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | Mortgage backed securities issued by United Sates government-sponsored enterprises

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | Money Market Funds

Financial assets and liabilities measured at fair value

Estimated Fair Value

132,495,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

^[1]

Fair Value, Inputs, Level 1 [Member] | US Treasury Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USTreasurySecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AssetBackedSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 1 [Member] | Foreign Government Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForeignGovernmentDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel1Member

Fair Value, Inputs, Level 2 [Member]

Financial assets and liabilities measured at fair value

Estimated Fair Value

4,288,900,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

750,320,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[2]

Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

2,186,311,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_CorporateDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[3]

Fair Value, Inputs, Level 2 [Member] | Mortgage backed securities issued by United Sates government-sponsored enterprises

Financial assets and liabilities measured at fair value

Estimated Fair Value

278,105,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[4]

Fair Value, Inputs, Level 2 [Member] | Money Market Funds

Financial assets and liabilities measured at fair value

Estimated Fair Value

0us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_MoneyMarketFundsMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

Fair Value, Inputs, Level 2 [Member] | US Treasury Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

536,364,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_USTreasurySecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[4]

Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

452,884,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_AssetBackedSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[4]

Fair Value, Inputs, Level 2 [Member] | Foreign Government Debt Securities

Financial assets and liabilities measured at fair value

Estimated Fair Value

$ 84,916,000us-gaap_AvailableForSaleSecurities
/ us-gaap_FairValueByAssetClassAxis
= us-gaap_ForeignGovernmentDebtSecuritiesMember
/ us-gaap_FairValueByFairValueHierarchyLevelAxis
= us-gaap_FairValueInputsLevel2Member

^[4]

[1]	Included in Cash Equivalents on the Consolidated Balance Sheet.
[2]	Includes $15.0 million in Cash Equivalents and $735.3 million in Marketable Securities on the Consolidated Balance Sheet.
[3]	Includes $147.2 million in Cash Equivalents and $2.0 billion in Marketable Securities on the Consolidated Balance Sheet.
[4]	Included in Marketable Securities on the Consolidated Balance Sheet.

X

- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=28360136&loc=d3e22054-111558



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (aa)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash

-URI http://asc.fasb.org/extlink&oid=6506951



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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Cash Equivalents

-URI http://asc.fasb.org/extlink&oid=6507016

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X

- Definition

Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Convertible Security

-URI http://asc.fasb.org/extlink&oid=6509036

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X

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400

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X

- Definition

Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.4)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 5

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563

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