Stockholders' Equity - Summary of Activities Related to Dividends on Common Stock (Detail) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Apr. 27, 2018	Apr. 28, 2017	Apr. 29, 2016
Dividends, Common Stock [Abstract]
Dividends per share declared	$ 0.80	$ 0.76	$ 0.72
Dividend payments	$ 214	$ 208	$ 210
Additional Paid-in Capital
Dividends, Common Stock [Abstract]
Dividend payments	106	88	125
Retained Earnings (Accumulated Deficit)
Dividends, Common Stock [Abstract]
Dividend payments	$ 108	$ 120	$ 85