Derivative Instruments (Derivatives Recorded At Fair Value) (Details) - USD ($) $ in Millions	Jul. 29, 2017	Jul. 30, 2016
Derivative [Line Items]
DERIVATIVE ASSETS	$ 149	$ 385
DERIVATIVE LIABILITIES	4	54
Derivatives designated as hedging instruments:
Derivative [Line Items]
DERIVATIVE ASSETS	148	384
DERIVATIVE LIABILITIES	1	53
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	46	7
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	1	53
Derivatives designated as hedging instruments: | Interest rate derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	0	11
Derivatives designated as hedging instruments: | Interest rate derivatives | Other assets
Derivative [Line Items]
DERIVATIVE ASSETS	102	366
Derivatives designated as hedging instruments: | Interest rate derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	0	0
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	1	1
DERIVATIVE LIABILITIES	3	1
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	1	0
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	3	1
Derivatives not designated as hedging instruments: | Equity derivatives | Other assets
Derivative [Line Items]
DERIVATIVE ASSETS	0	1
Derivatives not designated as hedging instruments: | Equity derivatives | Other long-term liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	$ 0	$ 0