Employee Benefit Plans - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 25, 2026	Jul. 26, 2025	Jul. 27, 2024
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 3,830	$ 3,641	$ 3,074
Income tax benefit for share-based compensation	1,175	871	696
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	589	584	514
Location, Statement of Income, Balance [Axis]: us-gaap:GeneralAndAdministrativeExpense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	448	476	375
Location, Statement of Income, Balance [Axis]: us-gaap:OperatingExpenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	3,241	3,057	2,560
Location, Statement of Income, Balance [Axis]: us-gaap:ResearchAndDevelopmentExpense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	1,734	1,625	1,316
Location, Statement of Income, Balance [Axis]: us-gaap:SellingAndMarketingExpense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	999	918	846
Location, Statement of Income, Balance [Axis]: csco:RestructuringAndOtherCharges
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	60	38	23
Product \| Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	254	255	214
Services \| Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 335	$ 329	$ 300