Investments, Investments Portfolio and AFS Continuous Unrealized Loss Position (Details) (USD $) In Millions, unless otherwise specified																							3 Months Ended
	Jul. 25, 2014	Apr. 25, 2014	Jul. 25, 2014 Available for Sale Securities	Apr. 25, 2014 Available for Sale Securities	Jul. 25, 2014 Corporate Debt Securities	Apr. 25, 2014 Corporate Debt Securities	Jul. 25, 2014 Auction Rate Securities	Apr. 25, 2014 Auction Rate Securities	Jul. 25, 2014 Mortgage Backed Securities	Apr. 25, 2014 Mortgage Backed Securities	Jul. 25, 2014 US Government and Agency Securities	Apr. 25, 2014 US Government and Agency Securities	Jul. 25, 2014 Foreign Government and Agency Securities	Apr. 25, 2014 Foreign Government and Agency Securities	Jul. 25, 2014 Certificates of Deposit	Apr. 25, 2014 Certificates of Deposit	Jul. 25, 2014 Other Asset-backed Securities	Apr. 25, 2014 Other Asset-backed Securities	Jul. 25, 2014 Debt Funds [Member]	Apr. 25, 2014 Debt Funds [Member]	Jul. 25, 2014 Exchange Traded Funds	Apr. 25, 2014 Exchange Traded Funds	Jul. 25, 2014 Debt Securities	Jul. 26, 2013 Debt Securities	Jul. 25, 2014 Equity Securities	Jul. 26, 2013 Equity Securities	Jul. 25, 2014 Nonrecurring	Apr. 25, 2014 Nonrecurring
Available-for-sale securities:
Available-for-sale securities, cost			$ 52	$ 47	$ 5,429	$ 5,504	$ 109	$ 109	$ 1,252	$ 1,337	$ 2,748	$ 3,138	$ 78	$ 67	$ 71	$ 54	$ 497	$ 540	$ 2,446	$ 2,143
Available-For-Sale Securities, Accumulated Gross Unrealized Gain, Before Tax			14	15	65	55	0	0	10	7	7	7	0	0	0	0	1	2	48	9
Available-For-Sale Securities, Accumulated Gross Unrealized Loss, Before Tax			(17)	(13)	(10)	(17)	(10)	(12)	(8)	(8)	(22)	(29)	0	0	0	0	0	0	(8)	(29)
Available-for-sale securities, fair value			49	49	5,484	5,542	99	97	1,254	1,336	2,733	3,116	78	67	71	54	498	542	2,486	2,123
Trading securities:
Trading securities, cost																					54	54
Trading securities, unrealized gains																					15	13
Trading securities, unrealized losses																					0	0
Trading securities, fair value																					69	67
Aggregate carrying amount of investments in equity and other securities that are accounted for using the cost or equity method	618	666																									618	666
Short-term and long-term investments, cost	13,354	13,659
Short-term and long-term investments, unrealized gains	160	108
Short-term and long-term investments, unrealized losses	(75)	(108)
Short-term and long-term investments, fair value	12,821	12,993
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	2,782	5,032	21	25	1,200	1,601	0	0	353	682	754	1,500							454	1,224
Available-For-Sale Securities, Continuous Unrealized Loss Position, Less Than 12 Months, Accumulated Loss	(27)	(90)	(17)	(13)	(5)	(14)	0	0	(3)	(7)	(1)	(27)							(1)	(29)
More than 12 months, fair value	1,630	221	0	0	273	50	99	97	333	28	784	46							141	0
Available-For-Sale Securities, Continuous Unrealized Loss Position, 12 Months Or Longer, Accumulated Loss	(48)	(18)	0	0	(5)	(3)	(10)	(12)	(5)	(1)	(21)	(2)							(7)	0
AFS Gross Realized Gain (Loss)
Proceeds from sales																							1,830	2,163	23	32
Gross realized gains																							11	6	19	18
Gross realized losses																							(3)	(5)	0	0
Impairment losses recognized																							$ 0	$ 0	$ (1)	$ 0