Borrowings (Schedule Of Short-Term Debt) (Details) - USD ($) $ in Millions	Jan. 27, 2018	Jul. 29, 2017
Short-term Debt [Line Items]
Amount	$ 13,741	$ 7,992
Current portion of long-term debt
Short-term Debt [Line Items]
Amount	$ 4,749	$ 4,747
Effective Rate	1.78%	1.66%
Commercial paper
Short-term Debt [Line Items]
Amount	$ 8,992	$ 3,245
Effective Rate	1.51%	1.16%