Fair Value Measurements, Fair Value Measured on Recurring Basis (Details) (USD $) In Millions, unless otherwise specified	Jul. 25, 2014	Apr. 25, 2014	Jul. 26, 2013	Apr. 26, 2013
Liabilities:
Contingent Consideration	$ 87	$ 68	$ 45	$ 142
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	1,135	1,251
Foreign government and agency securities	0	0
Certificates of deposit	0	0
Other asset-backed securities	0	0
Debt Funds	0	0
Marketable equity securities	49	49
Exchange-traded funds	69	67
Derivative Assets	96	89
Total assets	1,349	1,456
Liabilities:
Derivative liabilities	68	116
Contingent Consideration	0	0
Total liabilities	68	116
Recurring | Level 2
Assets:
Corporate debt securities	5,475	5,533
Auction rate securities	0	0
Mortgage-backed securities	1,254	1,336
U.S. government and agency securities	1,598	1,865
Foreign government and agency securities	78	67
Certificates of deposit	71	54
Other asset-backed securities	498	542
Debt Funds	2,486	2,123
Marketable equity securities	0	0
Exchange-traded funds	0	0
Derivative Assets	80	86
Total assets	11,540	11,606
Liabilities:
Derivative liabilities	0	11
Contingent Consideration	0	0
Total liabilities	0	11
Recurring | Level 3
Assets:
Corporate debt securities	9	9
Auction rate securities	99	97
Mortgage-backed securities	0	0
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	0	0
Marketable equity securities	0	0
Exchange-traded funds	0	0
Derivative Assets	0	0
Total assets	108	106
Liabilities:
Derivative liabilities	0	0
Contingent Consideration	87	68
Total liabilities	87	68
Recurring | Estimate of Fair Value, Fair Value Disclosure [Member]
Assets:
Corporate debt securities	5,484	5,542
Auction rate securities	99	97
Mortgage-backed securities	1,254	1,336
U.S. government and agency securities	2,733	3,116
Foreign government and agency securities	78	67
Certificates of deposit	71	54
Other asset-backed securities	498	542
Debt Funds	2,486	2,123
Marketable equity securities	49	49
Exchange-traded funds	69	67
Derivative Assets	176	175
Total assets	12,997	13,168
Liabilities:
Derivative liabilities	68	127
Contingent Consideration	87	68
Total liabilities	$ 155	$ 195