Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Shares of Common Stock	Common Stock and Additional Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Jul. 28, 2018		4,614
Beginning balance at Jul. 28, 2018	$ 43,204		$ 42,820	$ 1,233	$ (849)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,415			9,415
Other comprehensive income (loss)	121				121
Issuance of common stock (in shares)		48
Issuance of common stock	321		321
Repurchase of common stock (in shares)		(336)
Repurchase of common stock	(16,062)		(3,129)	(12,933)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(13)
Shares repurchased for tax withholdings on vesting of restricted stock units	(601)		(601)
Cash dividends declared	(4,489)			(4,489)
Share-based compensation	1,166		1,166
Ending balance (in shares) at Apr. 27, 2019		4,313
Ending balance at Apr. 27, 2019	36,804		40,577	(2,877)	(896)
Beginning balance (in shares) at Jan. 26, 2019		4,424
Beginning balance at Jan. 26, 2019	40,789		41,361	538	(1,110)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,044			3,044
Other comprehensive income (loss)	214				214
Issuance of common stock (in shares)		7
Issuance of common stock	$ 9		9
Repurchase of common stock (in shares)	(116)	(116)
Repurchase of common stock	$ (6,020)		(1,080)	(4,940)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(2)
Shares repurchased for tax withholdings on vesting of restricted stock units	(87)		(87)
Cash dividends declared	(1,519)			(1,519)
Share-based compensation	374		374
Ending balance (in shares) at Apr. 27, 2019		4,313
Ending balance at Apr. 27, 2019	$ 36,804		40,577	(2,877)	(896)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of adoption of accounting standards					(168)
Repurchase of common stock (in shares)	(82)
Ending balance (in shares) at Jul. 27, 2019		4,250
Ending balance at Jul. 27, 2019	$ 33,571		40,266	(5,903)	(792)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	8,578			8,578
Other comprehensive income (loss)	(317)				(317)
Issuance of common stock (in shares)		40
Issuance of common stock	335		335
Repurchase of common stock (in shares)		(59)
Repurchase of common stock	(2,619)		(561)	(2,058)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(11)
Shares repurchased for tax withholdings on vesting of restricted stock units	(519)		(519)
Cash dividends declared	(4,491)			(4,491)
Share-based compensation	1,170		1,170
Ending balance (in shares) at Apr. 25, 2020		4,220
Ending balance at Apr. 25, 2020	35,708		40,691	(3,874)	(1,109)
Beginning balance (in shares) at Jan. 25, 2020		4,241
Beginning balance at Jan. 25, 2020	35,533		40,617	(4,384)	(700)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,774			2,774
Other comprehensive income (loss)	(409)				(409)
Issuance of common stock (in shares)		6
Issuance of common stock	$ 1		1
Repurchase of common stock (in shares)	(25)	(25)
Repurchase of common stock	$ (981)		(236)	(745)
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)		(2)
Shares repurchased for tax withholdings on vesting of restricted stock units	(82)		(82)
Cash dividends declared	(1,519)			(1,519)
Share-based compensation	391		391
Ending balance (in shares) at Apr. 25, 2020		4,220
Ending balance at Apr. 25, 2020	35,708		$ 40,691	(3,874)	(1,109)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of adoption of accounting standards	$ 3,729			$ 3,897	$ (168)