Restructuring Charges - Activities Related to Restructuring Reserves (Detail) - USD ($) $ in Millions	3 Months Ended
	Jul. 26, 2019	Jul. 27, 2018
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	$ 19	$ 6
Net charges	21	19
Cash payments	(20)	(10)
Other	(4)	0
Balance at end of period	16	15
May 2019 Restructuring
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	0
Net charges	21
Cash payments	(11)
Other	0
Balance at end of period	10
April 2019 Restructuring
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	15
Net charges	0
Cash payments	(9)
Other	0
Balance at end of period	6
May 2018 Restructuring
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	0	0
Net charges	0	19
Cash payments	0	(9)
Other	0	0
Balance at end of period	0	10
November 2016 Restructuring
Restructuring Cost and Reserve [Line Items]
Balance at beginning of period	4	6
Net charges	0	0
Cash payments	0	(1)
Other	(4)	0
Balance at end of period	$ 0	$ 5