Fair Value Measurements, Fair Value Measured on Recurring Basis (Details) (USD $) In Millions, unless otherwise specified	Jan. 24, 2014	Oct. 25, 2013	Apr. 26, 2013	Jan. 25, 2013	Oct. 26, 2012	Apr. 27, 2012
Liabilities:
Business Combination, Contingent Consideration, Liability	$ 66	$ 45	$ 142	$ 141	$ 213	$ 231
Recurring | Level 1
Assets:
Corporate debt securities	0		0
Auction rate securities	0		0
Mortgage-backed securities	0		0
U.S. government and agency securities	1,523		1,833
Foreign government and agency securities	0		0
Certificates of deposit	0		0
Other asset-backed securities	0		0
Debt Funds Available-for-sale securities, fair value disclosure	0
Marketable equity securities	88		155
Exchange-traded funds	65		50
Derivative Assets	156		213
Total assets	1,832		2,251
Liabilities:
Derivative liabilities	97		40
Business Combination, Contingent Consideration, Liability	0		0
Total liabilities	97		40
Recurring | Level 2
Assets:
Corporate debt securities	5,498		4,651
Auction rate securities	0		0
Mortgage-backed securities	1,390		1,039
U.S. government and agency securities	2,017		2,065
Foreign government and agency securities	44		38
Certificates of deposit	6		6
Other asset-backed securities	655		541
Debt Funds Available-for-sale securities, fair value disclosure	1,169
Marketable equity securities	0		0
Exchange-traded funds	0		0
Derivative Assets	107		181
Total assets	10,886		8,521
Liabilities:
Derivative liabilities	14		18
Business Combination, Contingent Consideration, Liability	0		0
Total liabilities	14		18
Recurring | Level 3
Assets:
Corporate debt securities	9		10
Auction rate securities	96		103
Mortgage-backed securities	0		14
U.S. government and agency securities	0		0
Foreign government and agency securities	0		0
Certificates of deposit	0		0
Other asset-backed securities	0		0
Debt Funds Available-for-sale securities, fair value disclosure	0
Marketable equity securities	0		0
Exchange-traded funds	0		0
Derivative Assets	0		0
Total assets	105		127
Liabilities:
Derivative liabilities	0		0
Business Combination, Contingent Consideration, Liability	66		142
Total liabilities	66		142
Recurring | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets:
Corporate debt securities	5,507		4,661
Auction rate securities	96		103
Mortgage-backed securities	1,390		1,053
U.S. government and agency securities	3,540		3,898
Foreign government and agency securities	44		38
Certificates of deposit	6		6
Other asset-backed securities	655		541
Debt Funds Available-for-sale securities, fair value disclosure	1,169
Marketable equity securities	88		155
Exchange-traded funds	65		50
Derivative Assets	263		394
Total assets	12,823		10,899
Liabilities:
Derivative liabilities	111		58
Business Combination, Contingent Consideration, Liability	66		142
Total liabilities	$ 177		$ 200