Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jul. 28, 2018	Jul. 29, 2017	Apr. 28, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	17.30%	34.60%
Blended income tax rate, percent			30.50%
Tax Cuts And Jobs Act Of 2017,incomplete accounting, provisional income tax benefit			$ (76,648)
Tax Cuts And Jobs Act Of 2017, incomplete accounting, change in tax rate, deferred taxes, provisional income tax expense			81,871
Tax Cuts And Jobs Act Of 2017, incomplete accounting, transition tax for unremitted foreign earnings			(4,006)
Tax Cuts And Jobs Act of 2017, incomplete Accounting, transition tax withholding associated with repatriation of foreign earnings			$ 1,217