General - Computation of Basic and Diluted Earnings Per Share (EPS) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jan. 26, 2019	Jan. 27, 2018	Jan. 26, 2019	Jan. 27, 2018
Earnings Per Share [Abstract]
Denominator for basic earnings per share – weighted average shares (in shares)	92,818	91,949	92,677	92,674
Effect of dilutive securities - stock options, restricted stock and stock purchase plans (in shares)	835	660	670	649
Denominator for diluted earnings per share – weighted average shares (in shares)	93,653	92,609	93,347	93,323