Income Taxes - Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jan. 27, 2018	Apr. 28, 2018	Apr. 29, 2017	Apr. 30, 2016
Income Tax Disclosure [Abstract]
Effective income tax rate		(12.10%)	30.70%
Blended tax rate		30.50%
Tax Cuts And Jobs Act Of 2017, provisional income tax benefit	$ 77,256	$ 76,648,000
Tax Cuts And Jobs Act Of 2017, change in tax rate, deferred taxes, provisional income tax expense		81,871,000
Tax Cuts And Jobs Act Of 2017, transition tax on unremitted foreign earnings		(4,006,000)
Tax Cuts And Jobs Act of 2017, withholding tax on distributions		1,217,000
Tax Credit Carryforward [Line Items]
Foreign net operating loss carryforwards		13,830,000
Repatriation of foreign earnings		200,000,000
Tax impact of repatriation of foreign earnings			$ (2,406,000)	$ 12,300,000
Gross unrecognized tax benefits		14,227,000	14,211,000	$ 13,560,000
Deferred tax assets, deductibility of gross liabilities		2,418,000	3,883,000
Interest and penalties		1,764,000	$ 1,568,000
Increase in interest and penalties expense		$ 428,000
Foreign Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Expiration period		8 years
Capital Loss Carryforward
Tax Credit Carryforward [Line Items]
Expiration period		5 years