Investment Securities (Narrative) (Details) - USD ($)	9 Months Ended
Feb. 29, 2020	Mar. 02, 2019
Current Assets
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale of available-for-sale securities	$ 181,500,000	$ 160,200,000
Gross realized gains on sales of available-for-sale securities	246,000	7,000
Gross realized losses on sales of available-for-sale securities	7,000	35,000
Noncurrent Assets
Debt Securities, Available-for-sale [Line Items]
Proceeds from sale of available-for-sale securities	1,200,000	84,000
Gross realized gains on sales of available-for-sale securities	611,000	48,000
Gross realized losses on sales of available-for-sale securities	$ 0	$ 0

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

No definition available.

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- Definition

This item represents the gross loss realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

No definition available.

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- Definition

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26853-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3179-108585

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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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