Revenue - Disaggregation of Net Sales by Market Geography for Each Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 26, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 6,507	$ 7,493
U.S.
Disaggregation of Revenue [Line Items]
Net sales	3,351	3,918
Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	2,175	2,377
Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	981	1,198
Cardiac & Vascular Group
Disaggregation of Revenue [Line Items]
Net sales	2,433	2,790
Cardiac & Vascular Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	1,206	1,361
Cardiac & Vascular Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	853	930
Cardiac & Vascular Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	374	499
Minimally Invasive Therapies Group
Disaggregation of Revenue [Line Items]
Net sales	1,801	2,100
Minimally Invasive Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	722	913
Minimally Invasive Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	719	791
Minimally Invasive Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	359	396
Restorative Therapies Group
Disaggregation of Revenue [Line Items]
Net sales	1,712	2,012
Restorative Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	1,136	1,338
Restorative Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	376	426
Restorative Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	199	248
Diabetes Group
Disaggregation of Revenue [Line Items]
Net sales	562	592
Diabetes Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales	287	306
Diabetes Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales	226	231
Diabetes Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales	$ 48	$ 55