Investment Securities (Narrative) (Details) - USD ($) |
6 Months Ended | ||
|---|---|---|---|
Nov. 26, 2022 |
Nov. 27, 2021 |
May 28, 2022 |
|
| Investments Securities [Abstract] | |||
| Proceeds from sale of available-for-sale securities, current | $ 65,300,000 | $ 67,900,000 | |
| Proceeds from sale of available-for-sale securities, noncurrent | 0 | 453,000 | |
| Gross realized gains on sales of available-for-sale securities, current | 2,000 | 165,000 | |
| Gross realized gains on sales of available-for-sale securities, noncurrent | 165,000 | ||
| Gross realized losses on sales of available-for-sale securities, current | 63,000 | 67,000 | |
| Gross realized losses on sales of available-for-sale securities, noncurrent | $ 0 | ||
| Allowance for credit losses | $ 0 | $ 0 | |