General - Computation of Basic and Diluted Earnings Per Share (EPS) (Detail) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Jan. 27, 2018	Jan. 28, 2017	Jan. 27, 2018	Jan. 28, 2017
Earnings Per Share [Abstract]
Denominator for basic earnings per share – weighted average shares (in shares)	91,949	94,737	92,674	95,252
Effect of dilutive securities - stock options, restricted stock and stock purchase plans (in shares)	660	622	649	663
Denominator for diluted earnings per share – weighted average shares (in shares)	92,609	95,359	93,323	95,915