Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Jan. 23, 2016	Jul. 25, 2015
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 325	$ 302
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized (in shares)	5	5
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	20,000	20,000
Common stock, shares issued (in shares)	5,052	5,085
Common stock, shares outstanding (in shares)	5,052	5,085