Fair Value Measurements, Fair Value Measured on Recurring Basis (Details) (USD $) In Millions, unless otherwise specified	Oct. 24, 2014	Jul. 25, 2014	Apr. 25, 2014	Oct. 25, 2013	Jul. 26, 2013	Apr. 26, 2013
Liabilities:
Contingent Consideration	$ 91	$ 87	$ 68	$ 45	$ 45	$ 142
Recurring
Assets:
Corporate debt securities	5,653		5,542
Auction rate securities	99		97
Mortgage-backed securities	1,264		1,336
U.S. government and agency securities	2,860		3,116
Foreign government and agency securities	80		67
Certificates of deposit	46		54
Other asset-backed securities	471		542
Debt Funds	2,742		2,123
Marketable equity securities	46		49
Exchange-traded funds	70		67
Derivative Assets	350		175
Total assets	13,681		13,168
Liabilities:
Derivative liabilities	57		127
Contingent Consideration	91		68
Total liabilities	148		195
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	1,199		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	46		49
Exchange-traded funds	70		67
Derivative Assets	260		89
Total assets	1,575		1,456
Liabilities:
Derivative liabilities	27		116
Contingent Consideration	0		0
Total liabilities	27		116
Recurring | Level 2
Assets:
Corporate debt securities	5,644		5,533
Auction rate securities	0		0
Mortgage-backed securities	1,264		1,336
U.S. government and agency securities	1,661		1,865
Foreign government and agency securities	80		67
Certificates of deposit	46		54
Other asset-backed securities	471		542
Debt Funds	2,742		2,123
Marketable equity securities	0		0
Exchange-traded funds	0		0
Derivative Assets	90		86
Total assets	11,998		11,606
Liabilities:
Derivative liabilities	30		11
Contingent Consideration	0		0
Total liabilities	30		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	91		68
Total liabilities	$ 91		$ 68