Investments (Details) - USD ($) $ in Thousands	Oct. 29, 2022	Apr. 30, 2022
Short-term investments:
Total short-term investments		$ 24,716
Long-term investments:
Equity Method Investments.	$ 16,434	15,433
Total long-term investments	22,462	15,433
Investment in limited partnership fund
Long-term investments:
Equity Method Investments.	16,434	15,433
Available-for-sale securities.
Short-term investments:
Total short-term investments		24,716
Long-term investments:
Total long-term investments	6,028
Available-for-sale securities. | Municipal securities
Short-term investments:
Total short-term investments		19,725
Available-for-sale securities. | U.S. government securities
Short-term investments:
Total short-term investments		$ 4,991
Available-for-sale securities. | Equity securities
Long-term investments:
Total long-term investments	$ 6,028