Restructuring Charges, Net - Restructuring Reserve (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
	Jan. 26, 2015	Jan. 29, 2016	Oct. 30, 2015	Jul. 31, 2015	Apr. 24, 2015	Jan. 29, 2016
Restructuring Reserve [Roll Forward]
Reversal of excess accrual		$ (19)				$ (32)
Cost Synergies Initiative [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		156	$ 127	$ 143		143
Restructuring charges		55	86	67
Payments/write-downs		(50)	(44)	(83)
Reversal of excess accrual		(19)	(13)
Ending balance		142	156	127	$ 143	142
Cost Synergies Initiative [Member] | Employee Termination Costs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		135	112	136		136
Restructuring charges		36	64	52
Payments/write-downs		(30)	(28)	(76)
Reversal of excess accrual		(17)	(13)
Ending balance		124	135	112	136	124
Cost Synergies Initiative [Member] | Asset Write-downs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		0	0	0		0
Restructuring charges		12	10	0		22
Payments/write-downs		(12)	(10)	0
Reversal of excess accrual		0	0
Ending balance		0	0	0	0	0
Cost Synergies Initiative [Member] | Other Costs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		21	15	7		7
Restructuring charges		7	12	15
Payments/write-downs		(8)	(6)	(7)
Reversal of excess accrual		(2)	0
Ending balance		18	21	15	7	18
Covidien Initiative [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		46	60	78		78
Payments/write-downs		(14)	(14)	(18)
Reversal of excess accrual		(2)			(5)
Ending balance	$ 103	30	46	60	78	30
Covidien Initiative [Member] | Employee Termination Costs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		40	48	61		61
Restructuring charges	76
Payments/write-downs		(12)	(8)	(13)
Reversal of excess accrual		(2)
Ending balance		26	40	48	61	26
Covidien Initiative [Member] | Other Costs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance		6	12	17		17
Restructuring charges	$ 27
Payments/write-downs		(2)	(6)	(5)
Reversal of excess accrual		0
Ending balance		$ 4	$ 6	$ 12	$ 17	$ 4