Investments and Fair Value Measurements-AFS Investments (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 28, 2014	Dec. 29, 2013
Fixed Income Securities [Member]
Available-for-sale investments
Amortized Cost	$ 4,233,395	$ 5,128,833
Gross Unrealized Gain	10,106	20,599
Gross Unrealized Loss	(4,740)	(4,179)
Fair Value	4,238,761	5,145,253
U.S. Treasury securities [Member]
Available-for-sale investments
Amortized Cost	25,194	160,598
Gross Unrealized Gain	0	21
Gross Unrealized Loss	(32)	(424)
Fair Value	25,162	160,195
U.S. Government-sponsored agency securities [Member]
Available-for-sale investments
Amortized Cost	7,511	8,112
Gross Unrealized Gain	0	10
Gross Unrealized Loss	(18)	(1)
Fair Value	7,493	8,121
International Government Securities [Member]
Available-for-sale investments
Amortized Cost	82,033	38,492
Gross Unrealized Gain	0	1
Gross Unrealized Loss	(314)	(224)
Fair Value	81,719	38,269
Corporate notes and bonds [Member]
Available-for-sale investments
Amortized Cost	774,869	864,331
Gross Unrealized Gain	325	1,504
Gross Unrealized Loss	(2,052)	(1,565)
Fair Value	773,142	864,270
Asset-backed securities [Member]
Available-for-sale investments
Amortized Cost	171,221	226,620
Gross Unrealized Gain	42	114
Gross Unrealized Loss	(353)	(170)
Fair Value	170,910	226,564
Mortgage-backed securities [Member]
Available-for-sale investments
Amortized Cost	48,378	86,542
Gross Unrealized Gain	6	18
Gross Unrealized Loss	(173)	(554)
Fair Value	48,211	86,006
Municipal notes and bonds [Member]
Available-for-sale investments
Amortized Cost	3,124,189	3,744,138
Gross Unrealized Gain	9,733	18,931
Gross Unrealized Loss	(1,798)	(1,241)
Fair Value	$ 3,132,124	$ 3,761,828

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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.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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-Paragraph 1

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Amount of debt securities categorized neither as held-to-maturity nor trading.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

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Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities.

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Amount of unrealized loss before deducting unrealized gain on investments in available-for-sale securities.

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