Acquisitions and Acquisition-Related Items , Contingent Consideration (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Apr. 26, 2013	Apr. 27, 2012
Reconciliation of Beginning and Ending Balances of Contingent Milestone Payments Associated with Acquisitions
Beginning Balance	$ 231	$ 325
Purchase price contingent consideration	3	2
Contingent milestone payments	(30)	(141)
Change in fair value of contingent consideration	(62)	45
Ending Balance	142	231
Recurring
Reconciliation of Beginning and Ending Balances of Contingent Milestone Payments Associated with Acquisitions
Ending Balance	142	231
Recurring | Level 3
Reconciliation of Beginning and Ending Balances of Contingent Milestone Payments Associated with Acquisitions
Ending Balance	142	231
Recurring | Level 3 | Revenue Milestone
Reconciliation of Beginning and Ending Balances of Contingent Milestone Payments Associated with Acquisitions
Ending Balance	138
Recurring | Level 3 | Revenue Milestone | Discounted Cash Flow | Minimum
Fair Value Inputs
Discount rate	13.00%
Probability of payment	100.00%
Projected fiscal year of payment	2014
Recurring | Level 3 | Revenue Milestone | Discounted Cash Flow | Maximum
Fair Value Inputs
Discount rate	24.00%
Probability of payment	100.00%
Projected fiscal year of payment	2019
Recurring | Level 3 | Product Development Milestone
Reconciliation of Beginning and Ending Balances of Contingent Milestone Payments Associated with Acquisitions
Ending Balance	$ 4
Recurring | Level 3 | Product Development Milestone | Discounted Cash Flow
Fair Value Inputs
Discount rate	5.90%
Probability of payment	100.00%
Projected fiscal year of payment	2016