|
Investments (Realized Net Gains (Losses) Related To Available-For-Sale Investments) (Detail) (USD $)
In Millions, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Oct. 27, 2012
|
Oct. 29, 2011
|
|
| Available-for-sale Securities, Gross Realized Gains | $ 72 | $ 236 |
| Available-for-sale Securities, Gross Realized Losses | 45 | 227 |
| Net gains (losses) on investments | 27 | 9 |
|
Publicly Traded Equity Securities [Member]
|
||
| Available-for-sale Securities, Gross Realized Gains | 10 | (16) |
|
Fixed Income Securities [Member]
|
||
| Available-for-sale Securities, Gross Realized Losses | $ 17 | $ 25 |