Composition Of Certain Financial Statement Captions (Schedule Of Amortized Cost And Estimated Fair Value Of Short-Term And Long-Term Available-For-Sale Investments Based On Stated Maturities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 28, 2012	Sep. 28, 2012
Composition Of Certain Financial Statement Captions [Abstract]
Amortized Cost, Due within 1 year	$ 118,494	$ 302,154
Amortized Cost, Due in 1 to 2 years	167,779	209,302
Amortized Cost, Due in 2 to 3 years	137,112	151,174
Amortized Cost, Total	423,385	662,630
Fair Value, Due within 1 year	118,681	302,693
Fair Value, Due in 1 to 2 years	168,010	209,871
Fair Value, Due in 2 to 3 years	137,267	151,743
Fair Value, Total	$ 423,958	$ 664,307

Composition Of Certain Financial Statement Captions (Schedule Of Amortized Cost And Estimated Fair Value Of Short-Term And Long-Term Available-For-Sale Investments Based On Stated Maturities) (Details) (USD $)
In Thousands, unless otherwise specified

Dec. 28, 2012

Sep. 28, 2012

Composition Of Certain Financial Statement Captions [Abstract]

Amortized Cost, Due within 1 year

$ 118,494

$ 302,154

Amortized Cost, Due in 1 to 2 years

167,779

209,302

Amortized Cost, Due in 2 to 3 years

137,112

151,174

Amortized Cost, Total

423,385

662,630

Fair Value, Due within 1 year

118,681

302,693

Fair Value, Due in 1 to 2 years

168,010

209,871

Fair Value, Due in 2 to 3 years

137,267

151,743

Fair Value, Total

$ 423,958

$ 664,307

- Definition

This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are classified neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

This item represents debt securities, at cost, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments, as defined), and fair value hedge accounting adjustments, if any, which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

- Definition

For an unclassified balance sheet, total of debt 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

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

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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-Name Statement of Financial Accounting Standard (FAS)

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-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 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-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 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

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-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 7: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

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-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 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-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 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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+ Details