Income Taxes - Deferred Income Taxes - Undistributed Earnings - Narrative (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Jul. 30, 2017	Jul. 31, 2016	Apr. 30, 2017
Income Taxes [Line Items]
Undistributed earnings from our foreign subsidiaries that will not be reinvested indefinitely	$ 150,800,000	$ 134,700,000	$ 146,900,000
Deferred tax liability, undistributed earnings from foreign subsidiaries	810,000	431,000	497,000
U.S. income and foreign withholding taxes	45,400,000	39,800,000	44,000,000
U.S. foreign income tax credits	$ 44,600,000	$ 39,400,000	43,500,000
Unconsolidated Joint Venture [Member] | Haiti [Member]
Income Taxes [Line Items]
Undistributed earnings of foreign subsidiaries to be reinvested indefinitely			$ 1,800,000