Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) (Schecule of amounts reclassified from AOCI) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Apr. 30, 2017	May 01, 2016	Apr. 30, 2017	May 01, 2016
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, before tax		$ 2	$ (3)	$ 9	$ (9)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, tax expense (benefit)		(1)	1	(3)	3
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, after-tax		1	(2)	6	(6)
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, before Tax, [Abstract]
Reclassification of prior service credit included in net earnings, before tax	[1]	(5)	(1)	(18)	(2)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Tax [Abstract]
Total Pension and Other Postretirement Benefit amortization included in net earnings, tax expense (benefit)		1	0	6	0
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract]
Total Pension and Other Postretirement Benefit amortization included in net earnings, net of tax		(4)	(1)	(12)	(2)
Foreign Exchange Contract [Member] | Cost Of Products Sold [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, before tax		1	(4)	5	(10)
Foreign Exchange Contract [Member] | Other Expenses/Income [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, before tax		0	0	1	(2)
Interest Rate Contract [Member] | Interest Expense [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract]
Reclassification adjustment for (gains) losses included in net earnings, before tax		$ 1	$ 1	$ 3	$ 3

[1] This is included in the components of net periodic benefit (income) / expense (see Note 8 for additional details).