Marketable Securities (Available For Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
Mar. 29, 2014	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 56,771	$ 56,401
Gross Unrealized Holding Gains	8,503	7,925
Gross Unrealized Holding Losses	(261)	(1,233)
Fair Value	65,013	63,093
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,198	970
Gross Unrealized Holding Gains	6,815	7,239
Fair Value	8,013	8,209
Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	55,573	55,431
Gross Unrealized Holding Gains	1,688	686
Gross Unrealized Holding Losses	(261)	(1,233)
Fair Value	$ 57,000	$ 54,884

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.2)

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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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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

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-Name Accounting Standards Codification

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