Borrowings - Schedule of Long-Term Debt (Details) - USD ($) $ in Millions	9 Months Ended
Apr. 25, 2020	Jul. 27, 2019
Debt Instrument [Line Items]
Total	$ 16,000	$ 20,500
Unaccreted discount/issuance costs	(90)	(100)
Hedge accounting fair value adjustments	174	73
Total	16,084	20,473
Current portion of long-term debt	4,506	5,998
Long-term debt	11,578	14,475
Floating Rate Notes 3-month LIBOR Plus 0.34% Due September 20, 2019
Debt Instrument [Line Items]
Amount	$ 0	$ 500
Effective Rate	0.00%	2.77%
Fixed-Rate Notes, 1.40%, Due September 20, 2019
Debt Instrument [Line Items]
Interest rate, stated percentage	1.40%
Amount	$ 0	$ 1,500
Effective Rate	0.00%	1.48%
Fixed-Rate Notes, 4.45%, Due January 15, 2020
Debt Instrument [Line Items]
Interest rate, stated percentage	4.45%
Amount	$ 0	$ 2,500
Effective Rate	0.00%	4.72%
Fixed-Rate Notes, 2.45%, Due June 15, 2020
Debt Instrument [Line Items]
Interest rate, stated percentage	2.45%
Amount	$ 1,500	$ 1,500
Effective Rate	2.54%	2.54%
Fixed-Rate Notes, 2.20%, Due February 28, 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	2.20%
Amount	$ 2,500	$ 2,500
Effective Rate	2.30%	2.30%
Fixed-Rate Notes, 2.90%, Due March 4, 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	2.90%
Amount	$ 500	$ 500
Effective Rate	1.76%	3.14%
Fixed-Rate Notes, 1.85%, Due September 20, 2021
Debt Instrument [Line Items]
Interest rate, stated percentage	1.85%
Amount	$ 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%
Amount	$ 500	$ 500
Effective Rate	1.85%	3.36%
Fixed-Rate Notes, 2.60%, Due February 28, 2023
Debt Instrument [Line Items]
Interest rate, stated percentage	2.60%
Amount	$ 500	$ 500
Effective Rate	2.68%	2.68%
Fixed-Rate Notes, 2.20%, Due September 20, 2023
Debt Instrument [Line Items]
Interest rate, stated percentage	2.20%
Amount	$ 750	$ 750
Effective Rate	2.27%	2.27%
Fixed-Rate Notes, 3.625%, Due March 4, 2024
Debt Instrument [Line Items]
Interest rate, stated percentage	3.625%
Amount	$ 1,000	$ 1,000
Effective Rate	1.87%	3.25%
Fixed-Rate Notes, 3.50%, Due June 15, 2025
Debt Instrument [Line Items]
Interest rate, stated percentage	3.50%
Amount	$ 500	$ 500
Effective Rate	2.01%	3.52%
Fixed-Rate Notes, 2.95%, Due February 28, 2026
Debt Instrument [Line Items]
Interest rate, stated percentage	2.95%
Amount	$ 750	$ 750
Effective Rate	3.01%	3.01%
Fixed-Rate Notes, 2.50%, Due September 20, 2026
Debt Instrument [Line Items]
Interest rate, stated percentage	2.50%
Amount	$ 1,500	$ 1,500
Effective Rate	2.55%	2.55%
Fixed-Rate Notes, 5.90%, Due February 15, 2039
Debt Instrument [Line Items]
Interest rate, stated percentage	5.90%
Amount	$ 2,000	$ 2,000
Effective Rate	6.11%	6.11%
Fixed-Rate Notes, 5.50%, Due January 15, 2040
Debt Instrument [Line Items]
Interest rate, stated percentage	5.50%
Amount	$ 2,000	$ 2,000
Effective Rate	5.67%	5.67%
LIBOR \| Floating Rate Notes 3-month LIBOR Plus 0.34% Due September 20, 2019
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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Amount, after accumulated amortization, of debt discount.

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