Derivative Instruments (Derivatives Recorded at Fair Value) (Details) - USD ($) $ in Millions	Jan. 27, 2018	Jul. 29, 2017
Derivative [Line Items]
DERIVATIVE ASSETS	$ 90	$ 149
DERIVATIVE LIABILITIES	76	4
Derivatives designated as hedging instruments:
Derivative [Line Items]
DERIVATIVE ASSETS	65	148
DERIVATIVE LIABILITIES	75	1
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	47	46
Derivatives designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	0	1
Derivatives designated as hedging instruments: | Total return swaps—deferred compensation | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	0	0
Derivatives designated as hedging instruments: | Total return swaps—deferred compensation | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	49	0
Derivatives designated as hedging instruments: | Interest rate derivatives | Other assets
Derivative [Line Items]
DERIVATIVE ASSETS	18	102
Derivatives designated as hedging instruments: | Interest rate derivatives | Other long-term liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	26	0
Derivatives not designated as hedging instruments:
Derivative [Line Items]
DERIVATIVE ASSETS	25	1
DERIVATIVE LIABILITIES	1	3
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	24	1
Derivatives not designated as hedging instruments: | Foreign currency derivatives | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	1	3
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation | Other current assets
Derivative [Line Items]
DERIVATIVE ASSETS	1	0
Derivatives not designated as hedging instruments: | Total return swaps—deferred compensation | Other current liabilities
Derivative [Line Items]
DERIVATIVE LIABILITIES	$ 0	$ 0