Fair Value - Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jul. 30, 2023	Apr. 30, 2023	Jul. 31, 2022
U.S. Government Money Market Fund [Member]
Assets:
Investments at fair value	$ 7,113	$ 7,649	$ 8,853
Growth Allocation Mutual Funds [Member]
Assets:
Investments at fair value	585	528	464
Moderate Allocation Mutual Fund [Member]
Assets:
Investments at fair value	52	86	82
Other [Member]
Assets:
Investments at fair value	245	208	168
Quoted prices in active markets for identical assets - Level 1 [Member] | U.S. Government Money Market Fund [Member]
Assets:
Investments at fair value	7,113	7,649	8,853
Quoted prices in active markets for identical assets - Level 1 [Member] | Growth Allocation Mutual Funds [Member]
Assets:
Investments at fair value	585	528	464
Quoted prices in active markets for identical assets - Level 1 [Member] | Moderate Allocation Mutual Fund [Member]
Assets:
Investments at fair value	52	86	82
Quoted prices in active markets for identical assets - Level 1 [Member] | Other [Member]
Assets:
Investments at fair value	$ 245	$ 208	$ 168