Derivative Instruments (Derivatives Recorded At Fair Value) (Details) - USD ($) $ in Millions	Apr. 30, 2016	Jul. 25, 2015
Derivative [Line Items]
DERIVATIVE ASSETS	$ 345	$ 218
DERIVATIVE LIABILITIES	4	12
Derivatives designated as hedging instruments:
Derivative [Line Items]
DERIVATIVE ASSETS	345	212
DERIVATIVE LIABILITIES	3	11
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	13	10
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	3	11
Derivatives designated as hedging instruments: | Interest rate derivatives | Other assets
Derivative [Line Items]
DERIVATIVE ASSETS	332	202
Derivatives designated as hedging instruments: | Interest rate derivatives | Other long-term liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	0	0
Derivatives not designated as hedging instruments:
Derivative [Line Items]
DERIVATIVE ASSETS	0	6
DERIVATIVE LIABILITIES	1	1
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	0	2
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	1	1
Derivatives not designated as hedging instruments: | Equity derivatives | Other assets
Derivative [Line Items]
DERIVATIVE ASSETS	0	4
Derivatives not designated as hedging instruments: | Equity derivatives | Other long-term liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	$ 0	$ 0