v2.4.0.6
Fair Value (Reconciliation For All Assets Measured At Fair Value On Recurring Basis Using Significant Unobservable Inputs (Level 3)) (Detail) (Level 3, USD $)
In Millions, unless otherwise specified
12 Months Ended
Jul. 28, 2012
Jul. 30, 2011
Assets And Liabilities At Fair Value On A Recurring Basis [Line Items]    
Beginning balance $ 123 $ 152
Included in other income, net 3 2
Included in other comprehensive income (3)  
Purchases, sales and maturities (15) (31)
Transfer into Level 2 (107)  
Ending balance 1 123
Losses attributable to assets still held   (1)
Asset-Backed Securities
   
Assets And Liabilities At Fair Value On A Recurring Basis [Line Items]    
Beginning balance 121 149
Included in other income, net 3 3
Included in other comprehensive income (3)  
Purchases, sales and maturities (14) (31)
Transfer into Level 2 (107)  
Ending balance   121
Derivative Assets
   
Assets And Liabilities At Fair Value On A Recurring Basis [Line Items]    
Beginning balance 2 3
Included in other income, net   (1)
Purchases, sales and maturities (1)  
Ending balance 1 2
Losses attributable to assets still held   $ (1)