Other Assets (Detail) - USD ($) $ in Thousands	Jul. 30, 2017	Apr. 30, 2017		Jul. 31, 2016
Other Assets, Noncurrent [Abstract]
Cash surrender value - life insurance	$ 376	$ 376		$ 358
Non-compete agreement, net	809	828		885
Customer relationships, net	651	664		702
Other	561	526		557
Other assets	$ 2,397	$ 2,394	[1]	$ 2,502

[1] Derived from audited financial statements.