|
Investments - Additional Information (Detail) (USD $)
|
3 Months Ended | ||
|---|---|---|---|
|
Oct. 26, 2013
|
Oct. 27, 2012
|
Jul. 27, 2013
|
|
| Schedule of Available-for-sale Securities [Line Items] | |||
| Average Balance Of Securities Lending | $ 600,000,000 | $ 800,000,000 | |
| Minimum market value percentage of loaned securities, required collateral | 102.00% | ||
| Secured lending transactions outstanding | 0 | 0 | |
|
Fixed Income Securities [Member]
|
|||
| Schedule of Available-for-sale Securities [Line Items] | |||
| Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities | 0 | ||
|
Equity Securities [Member]
|
|||
| Schedule of Available-for-sale Securities [Line Items] | |||
| Other than Temporary Impairment Losses, Investments, Available-for-sale Securities | $ 0 | ||