Investment Securities (Schedule Of Investment Securities) (Details) - USD ($) $ in Thousands	Nov. 28, 2020	May 30, 2020
Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 123,133	$ 152,773
Unrealized Gains	1,495	1,390
Unrealized Losses	7	0
Estimated Fair Value	124,621	154,163
Noncurrent Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,032	2,005
Unrealized Gains	1,281	744
Unrealized Losses	0	0
Estimated Fair Value	3,313	2,749
Municipal bonds \| Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	16,378	16,093
Unrealized Gains	84	86
Unrealized Losses	0	0
Estimated Fair Value	16,462	16,179
Commercial paper \| Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,743	6,965
Unrealized Gains	0	17
Unrealized Losses	7	0
Estimated Fair Value	3,736	6,982
Corporate bonds \| Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	98,355	125,594
Unrealized Gains	1,387	1,274
Unrealized Losses	0	0
Estimated Fair Value	99,742	126,868
Certificates of deposits \| Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	1,001	1,492
Unrealized Gains	1	0
Unrealized Losses	0	0
Estimated Fair Value	1,002	1,492
Asset backed securities \| Current Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	3,656	2,629
Unrealized Gains	23	13
Unrealized Losses	0	0
Estimated Fair Value	3,679	2,642
Mutual funds \| Noncurrent Assets
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	2,032	2,005
Unrealized Gains	1,281	744
Unrealized Losses	0	0
Estimated Fair Value	$ 3,313	$ 2,749

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

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- Definition

Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121645371&loc=d3e27161-111563

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- Definition

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

+ References

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- Definition

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

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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