Fair Value - Additional Information (Details) - USD ($)	12 Months Ended
	Jul. 25, 2020	Jul. 27, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, carrying value	$ 2,453,000,000	$ 2,789,000,000
Long term loan receivables and financed service contracts and others carrying value	4,500,000,000	3,700,000,000
Senior notes, carrying value	14,583,000,000	20,473,000,000
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior notes, fair value	17,400,000,000	22,100,000,000
Property Held for sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Property, carrying value	9,000,000
Nonrecurring | Property Held for sale | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment charge	65,000,000
IPR&D
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-lived intangible assets acquired	$ 0	$ 333,000,000