Shareholders' Equity (Additional Information) (Details) - USD ($) $ / shares in Units, shares in Millions		3 Months Ended		6 Months Ended
	Feb. 15, 2017	Jan. 28, 2017	Jan. 23, 2016	Jan. 28, 2017	Jan. 23, 2016
Class of Stock [Line Items]
Cash dividends paid per common share (in dollars per share)		$ 0.26	$ 0.21	$ 0.52	$ 0.42
Payments of dividends				$ 2,612,000,000	$ 2,133,000,000
Cash dividends declared (in dollars per share)				$ 0.52	$ 0.42
Authorized common stock repurchase amount		$ 112,000,000,000		$ 112,000,000,000
Remaining authorized repurchase amount		$ 13,400,000,000		$ 13,400,000,000
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)				14	16
Payments related to tax withholding for share-based compensation				$ 432,000,000	$ 412,000,000
Subsequent Event
Class of Stock [Line Items]
Cash dividends declared (in dollars per share)	$ 0.29