Fair Value Measurements, Fair Value Measured on Nonrecurring Basis and Financial Instruments Not Measured at Fair Value (Details) (USD $)	3 Months Ended		9 Months Ended
	Jan. 23, 2015	Jan. 24, 2014	Jan. 23, 2015	Jan. 24, 2014	Apr. 25, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate carrying amount of investments in equity and other securities that are accounted for using the cost or equity method	$ 458,000,000		$ 458,000,000		$ 666,000,000
Carrying amount of goodwill	10,950,000,000		10,950,000,000		10,593,000,000
Finite-Lived Intangible Assets, Net	2,175,000,000		2,175,000,000
Financial Instruments Not Measured at Fair Value
Long-term debt (including short-term portion), fair value	30,320,000,000		30,320,000,000		11,856,000,000
Long-term debt (including short-term portion), principal value	28,375,000,000		28,375,000,000		11,375,000,000
Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate carrying amount of investments in equity and other securities that are accounted for using the cost or equity method	458,000,000		458,000,000		666,000,000
Carrying amount of goodwill	10,950,000,000		10,950,000,000		10,593,000,000
Goodwill, Impairment Loss	0	0	0	0
Finite-Lived Intangible Assets, Net	2,175,000,000		2,175,000,000		2,167,000,000
Nonrecurring | Other Expense, Net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of cost method investments	1,000,000		14,000,000
Nonrecurring | Acquisition-related items
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)		194,000,000
Nonrecurring | Restructuring charges, net
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Long-Lived Assets Held-for-use			9,000,000
Nonrecurring | Ardian
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Intangible Assets Excluding Goodwill Measured on Nonrecurring Basis as Percentage of Total Intangible Assets Excluding Goodwill, Maximum		5.00%		5.00%
Nonrecurring | Ardian | Acquisition-related items
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)		41,000,000
Impairment of Long-Lived Assets Held-for-use		3,000,000		3,000,000
In Process Research and Development [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	164,000,000		164,000,000		119,000,000
In Process Research and Development [Member] | Nonrecurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	164,000,000		164,000,000		119,000,000
In Process Research and Development [Member] | Nonrecurring | Acquisition-related items
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of Intangible Assets (Excluding Goodwill)				$ 194,000,000