Revenue - Disaggregation of Net Sales by Market Geography for Each Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Apr. 26, 2019	Jan. 25, 2019	Oct. 26, 2018	Jul. 27, 2018	Apr. 27, 2018	Jan. 26, 2018	Oct. 27, 2017	Jul. 28, 2017	Apr. 26, 2019	Apr. 27, 2018	Apr. 28, 2017
Disaggregation of Revenue [Line Items]
Net sales	$ 8,146	$ 7,546	$ 7,481	$ 7,384	$ 8,144	$ 7,369	$ 7,050	$ 7,390	$ 30,557	$ 29,953	$ 29,710
U.S.
Disaggregation of Revenue [Line Items]
Net sales									16,194	15,875	16,663
Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales									9,631	9,627	9,085
Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales									4,732	4,451	3,962
Cardiac and Vascular Group
Disaggregation of Revenue [Line Items]
Net sales									11,505	11,354	10,498
Cardiac and Vascular Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales									5,750	5,681	5,454
Cardiac and Vascular Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales									3,767	3,790	3,393
Cardiac and Vascular Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales									1,988	1,883	1,651
Minimally Invasive Therapies Group
Disaggregation of Revenue [Line Items]
Net sales									8,478	8,716	9,919
Minimally Invasive Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales									3,630	3,804	5,049
Minimally Invasive Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales									3,250	3,378	3,479
Minimally Invasive Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales									1,598	1,534	1,391
Restorative Therapies Group
Disaggregation of Revenue [Line Items]
Net sales									8,183	7,743	7,366
Restorative Therapies Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales									5,478	5,164	5,012
Restorative Therapies Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales									1,759	1,720	1,588
Restorative Therapies Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales									946	859	766
Diabetes Group
Disaggregation of Revenue [Line Items]
Net sales									2,391	2,140	1,927
Diabetes Group | U.S.
Disaggregation of Revenue [Line Items]
Net sales									1,336	1,226	1,148
Diabetes Group | Non-U.S. Developed Markets
Disaggregation of Revenue [Line Items]
Net sales									855	739	625
Diabetes Group | Emerging Markets
Disaggregation of Revenue [Line Items]
Net sales									$ 200	$ 175	$ 154