Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Feb. 27, 2016	May. 30, 2015
Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 380,038	$ 249,896
Unrealized Gains	228	116
Unrealized Losses	1,356	51
Estimated Fair Value	378,910	249,961
Noncurrent Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,493	1,199
Unrealized Gains	$ 386	$ 548
Unrealized Losses
Estimated Fair Value	$ 1,879	$ 1,747
US Government Obligations [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,989	9,609
Unrealized Gains	$ 2	$ 21
Unrealized Losses
Estimated Fair Value	$ 10,991	$ 9,630
Municipal Bonds [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	79,951	76,228
Unrealized Gains	$ 226	$ 83
Unrealized Losses
Estimated Fair Value	$ 80,177	$ 76,311
Certificates Of Deposit [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		2,001
Unrealized Gains		$ 1
Unrealized Losses
Estimated Fair Value		$ 2,002
Commercial Paper [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 2,992	7,491
Unrealized Gains		$ 5
Unrealized Losses	$ 3
Estimated Fair Value	2,989	$ 7,496
Corporate Bonds [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 267,802	$ 136,411
Unrealized Gains
Unrealized Losses	$ 1,327	$ 47
Estimated Fair Value	266,475	136,364
Foreign Government Obligations [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 2,056	1,042
Unrealized Gains		$ 3
Unrealized Losses
Estimated Fair Value	$ 2,056	$ 1,045
Asset Backed Securities [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 12,687	$ 14,356
Unrealized Gains
Unrealized Losses	$ 1	$ 4
Estimated Fair Value	12,686	14,352
Mutual Funds [Member] \| Current Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 3,561	2,758
Unrealized Gains		$ 3
Unrealized Losses	$ 25
Estimated Fair Value	3,536	$ 2,761
Mutual Funds [Member] \| Noncurrent Assets [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,493	1,199
Unrealized Gains	$ 386	$ 548
Unrealized Losses
Estimated Fair Value	$ 1,879	$ 1,747

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
-Subparagraph (b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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