Income Taxes - Unrecognized Tax Benefit (Detail) - USD ($) $ in Thousands		12 Months Ended
		Apr. 29, 2018	Apr. 30, 2017	May 01, 2016
Income Tax Disclosure [Abstract]
beginning balance		$ 12,245	$ 14,897	$ 14,141
increases from prior period tax positions		350	854	454
decreases from prior period tax positions	[1]	(11,751)	(3,506)	(77)
increases from current period tax positions				379
ending balance		$ 844	$ 12,245	$ 14,897

[1] The $11.8 million reduction in our unrecognized income tax benefits during fiscal 2018 is mostly associated with the reduction in our U.S. Federal income tax rate pursuant to the Tax Act on the effective settlement on an IRS exam. The $3.5 million reduction in our unrecognized income tax benefits during fiscal 2017 is due to a lapse of applicable statute of limitations in a foreign jurisdiction.