Stockholders' Equity - Summary of Activities Related to Dividends on Common Stock (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Oct. 27, 2017	Oct. 28, 2016	Oct. 27, 2017	Oct. 28, 2016
Dividends, Common Stock [Abstract]
Dividends per share declared	$ 0.20	$ 0.19	$ 0.40	$ 0.38
Dividend payments			$ 108	$ 105
Additional Paid-in Capital
Dividends, Common Stock [Abstract]
Dividend payments				76
Retained Earnings
Dividends, Common Stock [Abstract]
Dividend payments			$ 108	$ 29