XML 128 R112.htm IDEA: XBRL DOCUMENT v3.7.0.1
Employee Benefit Plans (Additional Information - Stock Option Activity) (Details) - USD ($)
$ / shares in Units, shares in Millions, $ in Millions
12 Months Ended
Jul. 29, 2017
Jul. 30, 2016
Jul. 25, 2015
Jul. 28, 2017
Retirement Benefits [Abstract]        
Total pretax intrinsic value $ 283 $ 266 $ 434  
Closing stock price (in dollars per share)       $ 31.52
In-the-money exercisable stock option (in shares) 6      
Number exercisable (in shares)   64    
Weighted- average exercise price (in dollars per share)   $ 29.66