Leases - Supplemental Information (Details) $ in Millions	3 Months Ended
	Oct. 26, 2019 USD ($)
Leases [Abstract]
Weighted-average remaining lease term (in years)	4 years 2 months 12 days
Weighted-average discount rate	1.90%
Cash paid for amounts included in the measurement of lease liabilities — operating cash flows	$ 104
Right-of-use assets obtained in exchange for operating leases liabilities	$ 48