Schedule of Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Oct. 31, 2020	Apr. 24, 2020
Acquired assets:
Cash and cash equivalents		$ 3,404
Property and equipment		744
Goodwill		44,485
In-process research and development	$ 27,000	27,000
Other assets acquired		895
Total assets acquired		76,528
Liabilities assumed:
Accounts payable and other liabilities		1,562
Deferred tax liabilities		3,816
Net assets acquired		$ 71,150