Restructuring Charges, Net (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
	Apr. 24, 2015	Apr. 24, 2015	Jul. 25, 2014	Apr. 25, 2014	Apr. 24, 2015	Apr. 25, 2014
Fiscal Year 2015 Initiative
Changes in Restructuring Reserves
Balance as of			$ 0		$ 0
Restructuring charges	$ 248				248
Payments/Write-downs					(105)
Balance as of	143	$ 143		$ 0	143	$ 0
Fiscal Year 2015 Initiative | Employee Termination Costs
Changes in Restructuring Reserves
Balance as of			0		0
Restructuring charges	213				213
Payments/Write-downs					(77)
Balance as of	136	136		0	136	0
Fiscal Year 2015 Initiative | Asset Write-downs
Changes in Restructuring Reserves
Balance as of			0		0
Restructuring charges	28				28
Payments/Write-downs					(28)
Balance as of	0	0		0	0	0
Fiscal Year 2015 Initiative | Contract Termination and Other Costs
Changes in Restructuring Reserves
Balance as of			0		0
Restructuring charges					7
Payments/Write-downs					0
Balance as of	7	7		0	7	0
Covidien Initiative
Changes in Restructuring Reserves
Balance as of		103
Restructuring charges		0
Payments/Write-downs		(20)
Reversal of excess accrual		(5)
Balance as of	78	78			78
Covidien Initiative | Employee Termination Costs
Changes in Restructuring Reserves
Balance as of		76
Restructuring charges		0
Payments/Write-downs		(10)
Reversal of excess accrual		(5)
Balance as of	61	61			61
Covidien Initiative | Contract Termination and Other Costs
Changes in Restructuring Reserves
Balance as of		27
Restructuring charges		0
Payments/Write-downs		(10)
Reversal of excess accrual		0
Balance as of	17	17			17
Fiscal Year 2014 Initiative
Changes in Restructuring Reserves
Balance as of			75		75	0
Restructuring charges			38	116	38	116
Payments/Write-downs					(87)	(41)
Reversal of excess accrual					(17)
Balance as of	9	9		75	9	75
Fiscal Year 2014 Initiative | Employee Termination Costs
Changes in Restructuring Reserves
Balance as of			64		64	0
Restructuring charges				65	1	65
Payments/Write-downs					(44)	(1)
Reversal of excess accrual					(14)
Balance as of	7	7		64	7	64
Fiscal Year 2014 Initiative | Asset Write-downs
Changes in Restructuring Reserves
Balance as of			0		0	0
Restructuring charges				26	9	26
Payments/Write-downs					(9)	(26)
Reversal of excess accrual					0
Balance as of	0	0		0	0	0
Fiscal Year 2014 Initiative | Contract Termination and Other Costs
Changes in Restructuring Reserves
Balance as of			11		11	0
Restructuring charges			$ 28		28	25
Payments/Write-downs					(34)	(14)
Reversal of excess accrual					(3)
Balance as of	$ 2	$ 2		$ 11	$ 2	$ 11