Revenue - Disaggregation of Net Sales by Market Geography for Each Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 25, 2019	Oct. 26, 2018	Oct. 25, 2019	Oct. 26, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 7,706	$ 7,481	$ 15,199	$ 14,865
U.S.
Disaggregation of Revenue [Line Items]
Net sales	4,129	4,045	8,046	7,909
Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	2,315	2,282	4,692	4,688
Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	1,262	1,154	2,460	2,268
Cardiac and Vascular Group
Disaggregation of Revenue [Line Items]
Net sales	2,855	2,858	5,645	5,669
Cardiac and Vascular Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	1,455	1,482	2,816	2,871
Cardiac and Vascular Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	890	895	1,820	1,842
Cardiac and Vascular Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	510	481	1,009	956
Minimally Invasive Therapies Group
Disaggregation of Revenue [Line Items]
Net sales	2,142	2,047	4,242	4,099
Minimally Invasive Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	922	872	1,835	1,729
Minimally Invasive Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	782	772	1,573	1,600
Minimally Invasive Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	438	403	834	770
Restorative Therapies Group
Disaggregation of Revenue [Line Items]
Net sales	2,112	1,993	4,124	3,942
Restorative Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	1,440	1,357	2,778	2,651
Restorative Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	416	412	842	840
Restorative Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	256	224	504	451
Diabetes Group
Disaggregation of Revenue [Line Items]
Net sales	596	583	1,188	1,155
Diabetes Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	311	334	618	658
Diabetes Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	226	203	457	406
Diabetes Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	$ 59	$ 46	$ 113	$ 91