Borrowings (Schedule of Short-Term Debt) (Details) - USD ($) $ in Millions	Jul. 29, 2017	Jul. 30, 2016
Short-term Debt [Line Items]
Amount	$ 7,992	$ 4,160
Current portion of long-term debt
Short-term Debt [Line Items]
Amount	$ 4,747	$ 4,159
Effective Rate	1.66%	0.97%
Commercial paper
Short-term Debt [Line Items]
Amount	$ 3,245	$ 0
Effective Rate	1.16%	0.00%
Other notes and borrowings
Short-term Debt [Line Items]
Amount	$ 0	$ 1
Effective Rate	0.00%	2.08%