Investments, Investments Portfolio and AFS Continuous Unrealized Loss Position (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Oct. 26, 2012		Oct. 28, 2011		Oct. 26, 2012		Oct. 28, 2011		Apr. 27, 2012
Cost method, equity method, and other investments:
Cost method, equity method, and other investments, cost	$ 483				$ 483				$ 508
Cost method, equity method, and other investments, fair value	483				483				508
Short-term and long-term investments, cost	9,512				9,512				8,842
Short-term and long-term investments, unrealized gains	265				265				257
Short-term and long-term investments, unrealized losses	(45)				(45)				(50)
Short-term and long-term investments, fair value	9,732				9,732				9,049
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	2,441				2,441				961
Less than 12 months, unrealized losses	(8)				(8)				(11)
More than 12 months, fair value	232				232				209
More than 12 months, unrealized losses	(36)				(36)				(38)
AFS OTTI Losses
OTTI losses recognized in OCI	1		1		1		2
OTTI losses recognized in earnings	1		1		1		1
Total OTTI losses recognized	1		1		1		3
Salient and PEAK
Business Acquisition
Gain on previously held investments			38				38
Corporate Debt Securities
Available-for-sale securities:
Available-for-sale securities, cost	3,627				3,627				3,501
Available-for-sale securities, unrealized gains	75				75				47
Available-for-sale securities, unrealized losses	(5)				(5)				(7)
Available-for-sale securities, fair value	3,697				3,697				3,541
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	411				411				664
Less than 12 months, unrealized losses	(1)				(1)				(4)
More than 12 months, fair value	31				31				16
More than 12 months, unrealized losses	(4)				(4)				(3)
Auction Rate Securities
Available-for-sale securities:
Available-for-sale securities, cost	153				153				153
Available-for-sale securities, unrealized gains	0				0				0
Available-for-sale securities, unrealized losses	(24)				(24)				(26)
Available-for-sale securities, fair value	129				129				127
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	0				0				0
Less than 12 months, unrealized losses	0				0				0
More than 12 months, fair value	128				128				127
More than 12 months, unrealized losses	(24)				(24)				(26)
Mortgage Backed Securities
Available-for-sale securities:
Available-for-sale securities, cost	1,060				1,060				840
Available-for-sale securities, unrealized gains	9				9				9
Available-for-sale securities, unrealized losses	(9)				(9)				(10)
Available-for-sale securities, fair value	1,060				1,060				839
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	364				364				218
Less than 12 months, unrealized losses	(2)				(2)				(2)
More than 12 months, fair value	71				71				57
More than 12 months, unrealized losses	(7)				(7)				(8)
US Government and Agency Securities
Available-for-sale securities:
Available-for-sale securities, cost	3,501				3,501				3,046
Available-for-sale securities, unrealized gains	14				14				38
Available-for-sale securities, unrealized losses	(2)				(2)				0
Available-for-sale securities, fair value	3,513				3,513				3,084
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	1,648				1,648
Less than 12 months, unrealized losses	(2)				(2)
More than 12 months, fair value	0				0
More than 12 months, unrealized losses	0				0
Foreign Government and Agency Securities
Available-for-sale securities:
Available-for-sale securities, cost	47				47				67
Available-for-sale securities, unrealized gains	0				0				0
Available-for-sale securities, unrealized losses	0				0				0
Available-for-sale securities, fair value	47				47				67
Certificates of Deposit
Available-for-sale securities:
Available-for-sale securities, cost	6				6				47
Available-for-sale securities, unrealized gains	0				0				0
Available-for-sale securities, unrealized losses	0				0				0
Available-for-sale securities, fair value	6				6				47
Other Asset-backed Securities
Available-for-sale securities:
Available-for-sale securities, cost	490				490				535
Available-for-sale securities, unrealized gains	3				3				3
Available-for-sale securities, unrealized losses	(1)				(1)				(1)
Available-for-sale securities, fair value	492				492				537
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	0				0				55
Less than 12 months, unrealized losses	0				0				0
More than 12 months, fair value	2				2				9
More than 12 months, unrealized losses	(1)				(1)				(1)
Marketable Equity Securities
Available-for-sale securities:
Available-for-sale securities, cost	101				101				100
Available-for-sale securities, unrealized gains	162				162				158
Available-for-sale securities, unrealized losses	(3)				(3)				(5)
Available-for-sale securities, fair value	260				260				253
AFS Continuous Unrealized Loss Position
Less than 12 months, fair value	18				18				24
Less than 12 months, unrealized losses	(3)				(3)				(5)
More than 12 months, fair value	0				0				0
More than 12 months, unrealized losses	0				0				0
Exchange Traded Funds
Trading securities:
Trading securities, cost	44				44				45
Trading securities, unrealized gains	2				2				2
Trading securities, unrealized losses	(1)				(1)				(1)
Trading securities, fair value	45				45				46
Debt Securities
AFS Gross Realized Gain (Loss)
Proceeds from sales	3,382	[1]	1,406	[1]	4,800	[1]	2,967	[1]
Gross realized gains	24	[1]	14	[1]	41	[1]	24	[1]
Gross realized losses	(3)	[1]	(5)	[1]	(7)	[1]	(7)	[1]
Impairment losses recognized	0	[1]	0	[1]	0	[1]	(1)	[1]
Equity Securities
AFS Gross Realized Gain (Loss)
Proceeds from sales	41	[2]	12	[2],[3]	65	[2]	53	[2],[3]
Gross realized gains	29	[2]	50	[2],[3]	37	[2]	55	[2],[3]
Gross realized losses	0	[2]	0	[2],[3]	0	[2]	0	[2],[3]
Impairment losses recognized	$ (4)	[2]	$ (4)	[2],[3]	$ (10)	[2]	$ (4)	[2],[3]

[1] Includes available-for-sale debt securities.

[2] Includes marketable equity securities, cost method, equity method, exchange-traded funds, and other investments.

[3] As a result of the Salient and PEAK acquisitions, the Company recognized a non-cash gain of $38 million during the three months ended October 28, 2011 on its previously held minority investments.