Revenue Recognition - Summary of Contract Balances (Detail) - USD ($) $ in Thousands	Jan. 31, 2019	May 01, 2018	Apr. 30, 2018
Contract Balances:
Contract assets, current	$ 2,992	$ 3,815
Contract assets, long-term	1,051	332
Total contract assets	4,043	4,147
Deferred revenue, current	32,947	32,705	$ 33,226
Deferred revenue, long-term	0	147	$ 147
Total deferred revenue	$ 32,947	$ 32,852