Investments (Credit Losses for Fixed Income Securities) (Details) (USD $) In Millions	9 Months Ended
Apr. 30, 2011	May 01, 2010
Investments
Balance at beginning of period	$ (95)	$ (153)
Sales of other-than-temporarily impaired fixed income securities	52	20
Balance at end of period	$ (43)	$ (133)

Name:

csco_SalesOfOtherThanTemporarilyImpairedFixedIncomeSecurities

Namespace Prefix:

csco

Data Type:

xbrli:monetaryItemType

Balance Type:

debit

Period Type:

duration