Cash, Cash Equivalents and Investments (Details 1) (USD $) In Millions, unless otherwise specified	Jan. 27, 2013
Contractual maturities of investments
Due in one year or less, Cost	$ 200
Due in one year or less, Estimated Fair value	201
Due after one through five years, Cost	682
Due after one through five years, Estimated Fair Value	687
No single maturity date, Cost	385	[1]
No single maturity date, Estimated Fair Value	404	[1]
Investments maturities amortized cost	1,267
Investments maturities fair value	$ 1,292

[1] Securities with no single maturity date include publicly-traded and privately-held equity securities, and asset-backed and mortgage-backed securities.