Borrowings (Schedule of Long-Term Debt) (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 28, 2018	Jul. 29, 2017
Debt Instrument [Line Items]
Total	$ 25,750	$ 30,500
Unaccreted discount/issuance costs	(116)	(136)
Hedge accounting fair value adjustments	(65)	108
Total	25,569	30,472
Short-term debt	5,238	4,747
Long-term debt	20,331	25,725
Three-month LIBOR plus 0.60%
Debt Instrument [Line Items]
Notes	$ 0	$ 1,000
Effective Rate	0.00%	1.84%
Three-month LIBOR plus 0.31%
Debt Instrument [Line Items]
Notes	$ 0	$ 900
Effective Rate	0.00%	1.62%
Three-month LIBOR plus 0.50%
Debt Instrument [Line Items]
Notes	$ 500	$ 500
Effective Rate	2.86%	1.76%
Three-month LIBOR plus 0.34%
Debt Instrument [Line Items]
Notes	$ 500	$ 500
Effective Rate	2.71%	1.66%
Fixed Rate Notes, 1.40%, Due February 28, 2018
Debt Instrument [Line Items]
Interest rate, stated percentage	1.40%
Notes	$ 0	$ 1,250
Effective Rate	0.00%	1.47%
Fixed Rate Notes 1.65% Due June 2018
Debt Instrument [Line Items]
Interest rate, stated percentage	1.65%
Notes	$ 0	$ 1,600
Effective Rate	0.00%	1.72%
Fixed-Rate Notes, 4.95%, Due February 2019
Debt Instrument [Line Items]
Interest rate, stated percentage	4.95%
Notes	$ 2,000	$ 2,000
Effective Rate	5.17%	4.96%
Fixed-Rate Notes, 1.60%, Due February 2019
Debt Instrument [Line Items]
Interest rate, stated percentage	1.60%
Notes	$ 1,000	$ 1,000
Effective Rate	1.67%	1.67%
Fixed-Rate Notes, 2.125%, Due March 2019
Debt Instrument [Line Items]
Interest rate, stated percentage	2.125%
Notes	$ 1,750	$ 1,750
Effective Rate	2.71%	1.84%
FIxed Rate Notes 1.40% Due September 2019
Debt Instrument [Line Items]
Interest rate, stated percentage	1.40%
Notes	$ 1,500	$ 1,500
Effective Rate	1.48%	1.48%
Fixed-Rate Notes, 4.45%, Due January 2020
Debt Instrument [Line Items]
Interest rate, stated percentage	4.45%
Notes	$ 2,500	$ 2,500
Effective Rate	4.52%	3.84%
Fixed-Rate Notes, 2.45%, Due June 2020
Debt Instrument [Line Items]
Interest rate, stated percentage	2.45%
Notes	$ 1,500	$ 1,500
Effective Rate	2.54%	2.54%
Fixed-Rate Notes, 2.20%, Due February 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	2.20%
Notes	$ 2,500	$ 2,500
Effective Rate	2.30%	2.30%
Fixed-Rate Notes, 2.90%, Due March 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	2.90%
Notes	$ 500	$ 500
Effective Rate	2.86%	2.00%
Fixed Rate Notes, 1.85% Due September 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	1.85%
Notes	$ 2,000	$ 2,000
Effective Rate	1.90%	1.90%
Fixed-Rate Notes, 3.00%, Due June 15, 2022
Debt Instrument [Line Items]
Interest rate, stated percentage	3.00%
Notes	$ 500	$ 500
Effective Rate	3.11%	2.26%
Fixed-Rate Notes, 2.60%, Due February, 2023
Debt Instrument [Line Items]
Interest rate, stated percentage	2.60%
Notes	$ 500	$ 500
Effective Rate	2.68%	2.68%
Fixed Rate Notes 2.20%, Due September 2023
Debt Instrument [Line Items]
Interest rate, stated percentage	2.20%
Notes	$ 750	$ 750
Effective Rate	2.27%	2.27%
Fixed-Rate Notes,3.625%, Due March 2024
Debt Instrument [Line Items]
Interest rate, stated percentage	3.625%
Notes	$ 1,000	$ 1,000
Effective Rate	2.98%	2.12%
Fixed-Rate Notes,3.50%, Due June 15, 2025
Debt Instrument [Line Items]
Interest rate, stated percentage	3.50%
Notes	$ 500	$ 500
Effective Rate	3.27%	2.43%
Fixed-Rate Notes,2.95%, Due February, 2026
Debt Instrument [Line Items]
Interest rate, stated percentage	2.95%
Notes	$ 750	$ 750
Effective Rate	3.01%	3.01%
Fixed Rate Notes 2.50%, Due September 2026
Debt Instrument [Line Items]
Interest rate, stated percentage	2.50%
Notes	$ 1,500	$ 1,500
Effective Rate	2.55%	2.55%
Fixed-Rate Notes, 5.90%, Due February 2039
Debt Instrument [Line Items]
Interest rate, stated percentage	5.90%
Notes	$ 2,000	$ 2,000
Effective Rate	6.11%	6.11%
Fixed-Rate Notes, 5.50%, Due January 2040
Debt Instrument [Line Items]
Interest rate, stated percentage	5.50%
Notes	$ 2,000	$ 2,000
Effective Rate	5.67%	5.67%
LIBOR \| Three-month LIBOR plus 0.60%
Debt Instrument [Line Items]
Three-month LIBOR plus this percentage	0.60%
LIBOR \| Three-month LIBOR plus 0.31%
Debt Instrument [Line Items]
Three-month LIBOR plus this percentage	0.31%
LIBOR \| Three-month LIBOR plus 0.50%
Debt Instrument [Line Items]
Three-month LIBOR plus this percentage	0.50%
LIBOR \| Three-month LIBOR plus 0.34%
Debt Instrument [Line Items]
Three-month LIBOR plus this percentage	0.34%

Hedge accounting adjustment of the carrying amount of the 2011 and 2016 Notes

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount, after accumulated amortization, of debt discount.

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