Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Nov. 26, 2016	May 28, 2016
Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 180,436	$ 360,400
Unrealized Gains	91	170
Unrealized Losses	117	71
Estimated Fair Value	180,410	360,499
Noncurrent Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,448	1,448
Unrealized Gains	580	489
Unrealized Losses
Estimated Fair Value	2,028	1,937
US government and agency obligations \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	17,296	18,809
Unrealized Gains	0	5
Unrealized Losses	48	0
Estimated Fair Value	17,248	18,814
Municipal bonds \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	56,960	79,481
Unrealized Gains	90	162
Unrealized Losses	0	0
Estimated Fair Value	57,050	79,643
Corporate bonds \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	98,318	240,593
Unrealized Gains	0	0
Unrealized Losses	67	56
Estimated Fair Value	98,251	240,537
Foreign government obligations \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	2,021	2,044
Unrealized Gains	0	2
Unrealized Losses	2	0
Estimated Fair Value	2,019	2,046
Asset backed securities \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,841	15,908
Unrealized Gains	1	0
Unrealized Losses	0	15
Estimated Fair Value	5,842	15,893
Mutual funds \| Current Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		3,565
Unrealized Gains		1
Unrealized Losses		0
Estimated Fair Value		3,566
Mutual funds \| Noncurrent Assets
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,448	1,448
Unrealized Gains	580	489
Unrealized Losses	0	0
Estimated Fair Value	$ 2,028	$ 1,937

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
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