The senior unsecured term loan facility contains a financial covenant based on our maximum leverage ratio. Pursuant to this covenant, if our credit rating is less than BBB+ from Standard & Poor's and Baa1 from Moody's Investors Service, Inc and the amount borrowed under the facility is in excess of $500, we must maintain a leverage ratio below (i) for the last day of each quarter ending on or prior to April 30, 2020, 5.75:1.00, and (ii) thereafter, 5.25:1.00. Our leverage ratio is calculated based on the ratio of consolidated net debt to consolidated adjusted EBITDA, each as defined in the credit agreement for the senior unsecured term loan facility. The maximum leverage ratio covenant is incorporated into our U.S. and Canadian facilities for so long as that covenant is in effect under the senior unsecured term loan facility. In addition, the senior unsecured term loan facility contains other customary covenants and events of default for credit facilities of this type.

Domestic Line of Credit [Member]

Debt Instrument [Line Items]

Line of Credit Facility, Maximum Borrowing Capacity

$ 1,850

Line of Credit Facility, Expiration Date

Dec. 31, 2021

Line of Credit Facility Utilized Borrowing Capacity

$ 1

Foreign Line of Credit [Member] | Variable Interest Rate [Member]

Debt Instrument [Line Items]

Line of Credit Facility, Maximum Borrowing Capacity

$ 96

$ 125

Debt Instrument, Maturity Date

Jul. 15, 2019

Line of Credit, Current

$ 90

$ 0

$ 117

Line of Credit Facility, Interest Rate at Period End

3.17%

Short-term Borrowing and Long-term Debt (Narratives) (Details) $ in Millions, $ in Millions, $ in Millions	12 Months Ended
	Jul. 29, 2018 USD ($)	Jul. 30, 2017 USD ($)	Jul. 29, 2018 CAD ($)	Apr. 29, 2018 USD ($)	Jul. 30, 2017 AUD ($)
Debt Instrument [Line Items]
Debt, Current	$ 1,896	$ 1,037
Commercial Paper	1,140	$ 874
Letters of Credit Outstanding, Amount	$ 59
Long-term Debt, Gross				$ 5,300
Debt Instrument, Redemption Price, Percentage	101.00%
Long-term Debt, Maturities, Repayments of Principal in Year Two	$ 500
Long-term Debt, Maturities, Repayments of Principal in Year Three	2,651
Long-term Debt, Maturities, Repayments of Principal in Year Four	1
Long-term Debt, Maturities, Repayments of Principal in Year Five	1,651
Long-term Debt, Maturities, Repayments of Principal after Year Five	$ 3,254
Commercial Paper [Member]
Debt Instrument [Line Items]
Short-term Debt, Weighted Average Interest Rate, at Point in Time	2.54%	1.31%	2.54%		1.31%
Australian Notes [Member]
Debt Instrument [Line Items]
Short-term Bank Loans and Notes Payable	$ 348	$ 152			$ 190
Debt Instrument, Interest Rate, Stated Percentage		6.98%			6.98%
Debt Instrument, Maturity Date		Mar. 29, 2021
4.88% notes, due 2019
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.88%		4.88%
Debt Instrument, Maturity Date	Sep. 18, 2018
Long-term Debt, Gross	$ 207	$ 224			$ 280
Variable Interest Rate [Member]
Debt Instrument [Line Items]
Short-term Bank Loans and Notes Payable	$ 22	10
Variable Interest Rate Term Loan due 2021 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Mar. 26, 2021
Long-term Debt, Gross	$ 900	0		$ 900
Debt Instrument, Covenant Description	The senior unsecured term loan facility contains a financial covenant based on our maximum leverage ratio. Pursuant to this covenant, if our credit rating is less than BBB+ from Standard & Poor's and Baa1 from Moody's Investors Service, Inc and the amount borrowed under the facility is in excess of $500, we must maintain a leverage ratio below (i) for the last day of each quarter ending on or prior to April 30, 2020, 5.75:1.00, and (ii) thereafter, 5.25:1.00. Our leverage ratio is calculated based on the ratio of consolidated net debt to consolidated adjusted EBITDA, each as defined in the credit agreement for the senior unsecured term loan facility. The maximum leverage ratio covenant is incorporated into our U.S. and Canadian facilities for so long as that covenant is in effect under the senior unsecured term loan facility. In addition, the senior unsecured term loan facility contains other customary covenants and events of default for credit facilities of this type.
Domestic Line of Credit [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,850
Line of Credit Facility, Expiration Date	Dec. 31, 2021
Line of Credit Facility Utilized Borrowing Capacity	$ 1
Foreign Line of Credit [Member] \| Variable Interest Rate [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 96		$ 125
Debt Instrument, Maturity Date	Jul. 15, 2019
Line of Credit, Current	$ 90	$ 0	$ 117
Line of Credit Facility, Interest Rate at Period End	3.17%		3.17%