Fair Value Measurements - Investments (Details) (USD $)	3 Months Ended	12 Months Ended
Dec. 27, 2014	Mar. 29, 2014
Schedule of Available-for-sale Securities
Available-for-sale Securities, Debt Maturities, Next Twelve Months, Amortized Cost Basis	$ 11,100,000
Available for sale Securities Current
Schedule of Available-for-sale Securities
Cost	11,118,000	40,793,000
Unrealized Gain	6,000	13,000
Unrealized Loss	0	0
Fair Value	11,124,000	40,806,000
Available for sale Securities Current \| Commercial Paper
Schedule of Available-for-sale Securities
Cost	3,400,000	6,700,000
Unrealized Gain	0	0
Unrealized Loss	0	0
Fair Value	3,400,000	6,700,000
Available for sale Securities Current \| Government agencies
Schedule of Available-for-sale Securities
Cost	3,001,000	8,035,000
Unrealized Gain	0	2,000
Unrealized Loss	0	0
Fair Value	3,001,000	8,037,000
Available for sale Securities Current \| Corporate Bonds
Schedule of Available-for-sale Securities
Cost	852,000	17,321,000
Unrealized Gain	0	7,000
Unrealized Loss	0	0
Fair Value	852,000	17,328,000
Available for sale Securities Current \| Municipal Bonds
Schedule of Available-for-sale Securities
Cost	3,865,000	8,737,000
Unrealized Gain	6,000	4,000
Unrealized Loss	0	0
Fair Value	3,871,000	8,741,000
Available for sale Securities Non Current
Schedule of Available-for-sale Securities
Cost	0	3,976,000
Unrealized Gain	0	9,000
Unrealized Loss	0	0
Fair Value	0	3,985,000
Available for sale Securities Non Current \| Municipal Bonds
Schedule of Available-for-sale Securities
Cost		3,976,000
Unrealized Gain		9,000
Unrealized Loss		0
Fair Value		$ 3,985,000

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

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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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Amount after adjustments of available-for-sale debt securities at cost, maturing in the next fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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

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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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