Shareholders' Equity (Additional Information) (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended
	Oct. 28, 2017	Oct. 29, 2016
Stockholders' Equity Note [Abstract]
Cash dividends paid per common share (in dollars per share)	$ 0.29	$ 0.26
Payments of dividends	$ 1,436,000,000	$ 1,308,000,000
Authorized common stock repurchase amount	112,000,000,000
Remaining authorized repurchase amount	$ 10,100,000,000
Shares repurchased for tax withholdings on vesting of restricted stock units (in shares)	11	13
Payments related to tax withholding for share-based compensation	$ 342,000,000	$ 401,000,000