Balance Sheet Account Details (Details) (USD $) In Thousands, unless otherwise specified	Apr. 01, 2012	Jan. 01, 2012
Available-for-sale securities:
Available for sale securities, Amortized Cost	$ 1,004,610	$ 885,264
Available for sale securities, Gross Unrealized Gains	2,244	1,935
Available for sale securities, Gross Unrealized Losses	(685)	(609)
Available for sale securities, Estimated Fair Value	1,006,169	886,590
Debt securities in government sponsored entities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	402,474	393,759
Available for sale securities, Gross Unrealized Gains	441	428
Available for sale securities, Gross Unrealized Losses	(216)	(148)
Available for sale securities, Estimated Fair Value	402,699	394,039
Corporate debt securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	504,116	432,550
Available for sale securities, Gross Unrealized Gains	1,692	1,293
Available for sale securities, Gross Unrealized Losses	(379)	(461)
Available for sale securities, Estimated Fair Value	505,429	433,382
U.S. Treasury securities [Member]
Available-for-sale securities:
Available for sale securities, Amortized Cost	98,020	58,955
Available for sale securities, Gross Unrealized Gains	111	214
Available for sale securities, Gross Unrealized Losses	(90)	0
Available for sale securities, Estimated Fair Value	$ 98,041	$ 59,169

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

+ References+ Details

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

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

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 4: http://www.xbrl.org/2003/role/presentationRef

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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

-Name FASB Staff Position (FSP)

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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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-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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-Section 25

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+ Details

- Definition

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details